But on an unassuming street in Fitzrovia, sandwiched between a high-end gym and a nail salon, sits the locus of a Downing Street afterlife that defies easy description — and far exceeds any of these in the scale of its ambition.

“I always say to people, we’re not an NGO, we’re not a government department and we’re not a charity,” says Sir Tony Blair in that eminently reasonable, slightly effeminate diction that somehow flutters free of the heavy baggage that still surrounds his time in office. “We’re a not-for-profit, which means that any of the profits go back into the institute. But we expect people to… ”

Uncharacteristically, Labour’s only winner of three consecutive elections hesitates. Catherine Rimmer, formerly his No 10 chief of staff and now his chief executive, finishes the sentence for him: “To deliver.”

It took almost a decade after his retirement as prime minister for Blair to shape this peculiar beast. In 2016 he folded his various foundations and commercial activities — which had been channelled through companies with names that seemed to belong on brass plates in the Cayman Islands: Firerush Ventures and Windrush Ventures — into a single organisation: the Tony Blair Institute for Global Change.

The TBI, as it is known, is now active in almost 40 countries, with more than 800 staff and revenues that approached $140 million (£110 million) last year. It has big outposts in Abu Dhabi, Nairobi and Singapore, with another planned in Washington. From its London headquarters, Blair oversees an unofficial global government that gets involved in everything from guiding Saudi Arabia’s crown prince on modernisation to telling the UK how it should harness the promise of artificial intelligence.

His stardust has probably been a factor in its ability to hire the likes of General Sir Nick Carter, former chief of the defence staff, and Sir Patrick Vallance, the former chief scientific adviser. “You couldn’t get two more experienced people in their fields,” Blair says mildly of the recent double poaching. “We’ve got governments around the world that are worried about security or how they deal with science and technology. We’ve got two people we can offer them who’ve gone and done it.”

It was Boris Johnson who, as a child, wanted to be “world king”. But among Britain’s swelling ranks of ex-prime ministers, it is Blair who has come closest to seizing that crown.

The TBI’s overarching vision is the one Blair has been honing ever since he overtook Gordon Brown to claim the Labour leadership after the death of John Smith almost 30 years ago: that what wearied electorates really want and need is not ideology but — yes, you guessed it — apolitical delivery.

Clasping a black coffee on the light, bright second floor of his office, the TBI’s executive chairman declares that western democracy has “lost its sense of mission”.

“What brings good people in to any organisation, including government, is if they think there’s a plan, right?” he says. “What’s happened is that people have become — in my view misguidedly — pessimistic about what we can do and how we can alter the problems that we’ve got It is possible to make huge and deep-seated reform today — in public services, in government itself. The productivity of the economy could improve dramatically as a result of the application of technology.

“So it’s a really exciting world, but what I find quite interesting when I talk to people in politics is they’re a little depressed about the future. They think if you’re in government, there’s just a limit to what you can do — maybe you can squeeze a bit more of tax and spending here, or a bit less of it there. There’s no big mission. And I’m saying, there is a huge mission. We are undergoing this technology revolution, it’s going to accelerate and that’s the real-world event. Politicians often look at me a bit curiously and think, ‘Well, maybe he’s been too long out of the front line of politics.’ But I say to them, no — [technology] is going to change everything!”

As a result of all this Blair worries about the calibre of candidates wanting to enter public life today. “If you’re not careful there’s a real risk that politics will become a branch of celebrity,” he says. “So the people coming into politics are the weird and the wealthy.”

Really? This from the soundbite-happy prime minister who brought us “a new dawn”, “the people’s princess” and “the hand of history”? Some will roll their eyes at this perma-polished architect of the third way — the man whose embrace of globalisation, deregulation and high immigration arguably contributed to the 2008 financial crisis and even Brexit — returning to evangelise about technology’s power to rescue us from our malaise.

It’s true that New Labour’s former frontman has revived some of his favourite old tunes, such as the need for ID cards, announced in 2005 only to be neutered by his own side after he left office and then killed by the Conservatives. But the TBI’s contributions during the pandemic — including Blair’s personal call for first doses of Covid vaccines to be given to as many people as possible, quickly adopted by the government — reminded Britain that this was a serious person with the ability to think clearly in a crisis. The chaos of the Johnson administration cast New Labour’s cautious managerialism in a kinder light. Even if there was no forgiving or forgetting Blair’s tragic mistake in Iraq, the Chilcot inquiry — which finally concluded that his decision to go to war in 2003 was flawed — had provided a degree of closure. Iraq was beginning to be seen in the broader context of an unprecedented 13-year Labour rule that redrew the political landscape.

In 2003 a young barrister named Keir Starmer wrote an article warning the prime minister that invading in breach of international law would be “a precarious business”. In his biography of the Labour leader, the journalist Tom Baldwin writes that Sir Keir (who was knighted in 2014) initially kept his distance from his divisive predecessor and associates such as Lord Mandelson. The Momentum wing of the Labour Party, after all, hates Blair with an internecine ferocity the Tories could never match. Before he ran for the leadership after Labour’s crushing 2019 election defeat, Starmer was shadow Brexit secretary to the Momentum-backed Jeremy Corbyn.

Observers point out that Starmer has since made an “ascent of man” journey across the political spectrum — from winning the Labour leadership on a Corbyn-lite ticket, to engaging Brown for a review of constitutional reform, to getting cosy with Blair. Starmer sceptics see this as evidence of his ability to use people then drop them. Others see it as proof of Blair’s enduring magnetism. Perhaps it is a bit of both.

It is now widely acknowledged that, alongside the centre-left campaign group Labour Together and the left-leaning Resolution Foundation think tank, the TBI is likely to be a highly influential voice under a Labour government. Starmer, who shared a stage with Blair at the TBI’s Future of Britain conference last summer, has populated his team with Blairites — including the former Blair special adviser Matthew Doyle, now Starmer’s director of communications; the former Blair strategist and speechwriter Peter Hyman, who is a senior adviser; and another former Blair special adviser, Peter Kyle, now the shadow science secretary. In particular Kyle and Wes Streeting, the glossy shadow health secretary, are said to act as Blair’s emissaries around the shadow cabinet table.

Marianna McFadden, previously “head of insight” at the TBI, is deputy to Starmer’s campaign director, Morgan McSweeney. Working with them is Marianna’s husband, Pat McFadden, a Blair government veteran who is Labour’s election campaign chief. He says: “One of the good things Keir has done is to tell the Labour Party and the country that he’s really proud of what Labour’s done in government. We went through a period of time after 2010 when we weren’t telling the Labour Party and the country that, and that’s a welcome change.”

McFadden describes the TBI as a “useful resource for different members of the shadow cabinet”. “Curiosity is an essential function of leadership, and people who want to occupy positions of government responsibility have a duty to be curious about technological change,” he says. “In an era of tight money, where so much of the debate is around fiscal events and headroom, you need a broader debate. I’m not saying that public services don’t need investment — of course they do — but there is also going to be interest in how services can be reformed and whether technology can help you get greater productivity.”

With a deeply unpopular Conservative government almost visibly falling apart and Labour surfing double-digit poll leads, strains of D:Ream’s Things Can Only Get Better are once again in the air. But Starmer and Rachel Reeves, the shadow chancellor, lack Blair and Brown’s wattage. And with the collapse of its pledge to spend £28 billion a year on renewable energy, and the edges being sanded off deputy leader Angela Rayner’s package of workers’ rights reforms, Labour is missing a centrepiece policy.

Blair credits Starmer with yanking the party ruthlessly back into the mainstream. “There would have been a split in Labour if he hadn’t,” he says, “because in the end it would have become clear that you just couldn’t win with what you had.”

But does Starmer have ideas? The response is lukewarm. “I think he’s got ideas. The challenge for Labour is going to be how it inherits a situation that is economically very difficult, and then makes change against that background.”

Blair’s prescriptions are, unsurprisingly, technocratic. For example, the TBI has called for faster building of key infrastructure, claiming that since the national policy statements governing big energy projects were last updated in 2012, the average time it takes to obtain planning consent has gone up by 65 per cent. “The problem with progressive politics is very often that the radical people aren’t sensible, and the sensible people aren’t radical,” Blair says. “You put people in this situation where they’re either enthusiastic and misguided or they’re lacking in enthusiasm but then rather boring. You’ve got to define radical politics as not about spending money. The truth is, if you want to meet net zero, the single biggest thing you could do is reform a planning system that is utterly ridiculous It can take years, even if you build a renewable power plant, to get it on to the [National Grid]. These are the things that Labour should, and can, grapple with.”

There is also Britain’s relationship with Europe. “It would be wise to reset it,” Blair says. “There are too many things that affect us that are going on in Europe. That doesn’t mean to say [Starmer] will start trying to frame this as rejoining [the EU] or even the single market. In any event, we’ve got a trade negotiation coming up in 2025. But at the moment we’re outside the big political union on our own continent and we’ve got a disrupted trading relationship with our biggest trading partner, so you’ve got to fix this stuff. To be fair to [Rishi] Sunak, he’s trying to fix as much as he can, given the constraints he’s under from his own party.”

Blair at 70 looks like his photogenic younger self put through an Instagram ageing filter. The eyes are still earnest blue, the Spitting Image grin still framed by the distinctive ears. He is trim, albeit touched by a slight stiffness. But the mane has long since greyed. Chelsea boots add a louche touch he wouldn’t have got away with in the days of being tough on crime and its causes.

The former prime minister still criss-crosses the globe — San Francisco one day, Guyana the next. Someone in his extended circle says: “The gossip among the security people who look after former prime ministers is that you work for John Major, and one day at the cricket is quite fun, but do we have to go every day for five days? You work for Theresa May and you have a pretty quiet life. You work for Tony Blair and you’re bound to get divorced because you’re on the road 250 days a year, stepping in and out of a private jet every two days. It’s great fun but your marriage doesn’t last.”

Blair still receives the digital equivalent of the prime ministerial “box” he used to get before heading from No 10 to Chequers for the weekend. The TBI’s staff send him “a whole stack of reports — what we’re doing in Africa, what we’re doing in Asia”. Why expend all this energy when he could be following Major or May’s examples and adjusting his work/life balance? “If you’ve had the get-up-and-go to go into politics and then you become prime minister for ten years, it’s frankly unlikely that when you finish you’ll just want to sit back,” Blair says. “People always want to ascribe some sort of malign, or let’s say benign but psychological motive to it. I came into politics because I wanted to make a difference and I still want to. Now I can do it in a different way.”

There is a sense of unfinished business, though. In 2009 he tried and failed to become the first president of the European Council, a platform he says he would have used to “try to put Europe on a path of reform”. A close friend says it took Blair years after leaving parliament to accept that he would never return to a frontline role in British politics. He often remarks, wistfully, that he knew the least about how to get things done when he was at the peak of his popularity in the late 1990s — and the most just at the point when he was forced out.

In 1999 he complained about the “scars on my back” after two years of trying to modernise public services, prompting a row with unions. He doubled down at the Labour conference that September, attacking the “forces of conservatism” — small C — that he said were holding back progress. Blair’s autobiography, A Journey, details how Brown’s resistance to reforms such as introducing more patient choice into the NHS — which he apparently dubbed “marketisation” — morphed into an “enervating and depressing” struggle over ID cards. Badly wounded by Iraq, Blair eventually lost his long arm-wrestle with Brown over the leadership and resigned in 2007, to a standing ovation from the Commons but chuntering from many on his own benches. He then had to watch from the sidelines as — in his view — his political partner of more than two decades ditched their modernising project and reverted to “Old Labour”.

Blair and his wife, Cherie, had already bought a townhouse on London’s Connaught Square, in Bayswater. They followed that with a mansion in Buckinghamshire previously owned by the actor Sir John Gielgud. Hours after he stood down as prime minister, Blair was named Middle East envoy for the quartet of the US, the EU, the UN and Russia. He accepted advisory roles with the Wall Street bank JP Morgan and Zurich Financial Services; he continues with the former but the latter ended more than a decade ago.

Less than two years after Cameron led his MPs in applauding the opponent he taunted as having been “the future, once”, parliament’s appointments watchdog posted a statement on its website noting that Blair had established Tony Blair Associates. He planned to use the new firm to provide clients with “strategic advice on a commercial and pro-bono basis”. It sounded like Kissinger Associates, the geopolitical consultancy created by the 20th century’s realpolitik pioneer. Indeed, Henry Kissinger seems to have been an inspiration. After Kissinger died last November, Blair said he had been “in awe of him”, adding: “If it is possible for diplomacy, at its highest level, to be a form of art, Henry was an artist.”

Set up with help from the accountancy firm KPMG, TBA seemed designed to frustrate Blair’s critics from the outset. Although it was onshore, its complex and opaque structure meant he got close to tax-haven levels of privacy. Early contracts to advise the government of Kuwait and the Abu Dhabi-based sovereign wealth fund Mubadala led to accusations of conflicts of interest with his Middle East brief. Blair then helped the autocratic president of Kazakhstan, Nursultan Nazarbayev, handle the fallout after Kazakh security forces shot dead 14 protesters during an anti-government uprising in 2011. Commercial dealmaking as an intermediary in the mining giant Glencore’s takeover of its rival Xstrata, and in a battle over ownership of Claridge’s hotel, added to the image of a former prime minister grubbing for money, although Blair used the proceeds as seed funding for the TBI.

In 2016 Blair said he wanted to “re-orient our mission” by rolling everything into his institute. In some ways it has continued with the spirit of what might be called Kissingerian pragmatism. It kept advising Saudi Arabia and its Crown Prince Mohammed bin Salman after the murder of the dissident journalist Jamal Khashoggi, telling The Sunday Times last year that “staying engaged there is justified”, despite the “terrible” killing. Its donors include the American tech billionaire Larry Ellison, whose foundation has given the TBI more than $100 million and pledged a further $272 million. The TBI and Oracle, which Ellison chairs, have given free cloud-based technology for ten years to Ghana, Rwanda and Senegal so they can manage vaccination records digitally. Oracle has a commercial interest in electronic health records, having bought the healthcare software specialist Cerner for $28.3 billion in 2022.

“There’s no lack of transparency,” Blair insists when it comes to Ellison. “We have a partnership with Larry. He gives a generous donation to the institute. But whenever we’re in a situation where any of his own companies are concerned, we’ll always be completely open about the relationship we have with them. It’s important to do that, but they’re actually good companies.”

In other ways the TBI is an altogether shinier affair than its forebear. It is run by Rimmer, who was head of Blair’s Downing Street research unit. In charge of its government advisory work is Michael McNair, a former policy chief to the Canadian prime minister Justin Trudeau. Its head of strategy, Awo Ablo, is vice-chairwoman of the BBC’s Media Action charity and happens to sit on the board of Oracle. The TBI’s roster of counsellors includes Sanna Marin, the former Finnish prime minister.

The bosses of other think tanks regard its resource base and salary levels with envy. Accounts for 2022 show the TBI paid staff an average of $92,650. Its highest-remunerated director received $662,000. Blair does not take a salary. Rimmer says its government advisory teams are based in the relevant countries — “we don’t do ‘fly in, fly out’ ”. “They work in the office of the president or prime minister — we ask for desk space in those offices,” she says. “It’s not tinkering around in departments. The way we pitch it to governments is, ‘We will work with you on strategy, policy and delivery, with technology as an enabler of all three.’ It starts with the strategy. I don’t really think other consultancies do that.”

The TBI has a big presence in Abu Dhabi and Singapore. Blair seems drawn to the model of benevolent dictatorship. “With Covid, the countries that did well are exactly the countries you’d expect to do well,” he says, laughing. “It’s no great mystery. Did Singapore do well? Yep. Did the UAE do well? Yep. We did actually averagely well, frankly. We weren’t at the top but we weren’t at the bottom either.”

Blair remarks that Sunak is the fifth prime minister in eight years — and “surprisingly enough, we’ve got a lot of problems”. He says “democracy is ultimately what people want, because the problem with countries that aren’t democracies is they’re fine if you happen to have really smart people running them, but if you don’t, there’s a problem”.

“Democracy can deliver, but it’s got a problem today because it is an old-fashioned politics trying to deal with a very new-fashioned world,” he says. “That’s why the right is defaulting to nationalistic policies, which are just a dead end. And the left is struggling — one part of it has gone for identity politics, which is another cul-de-sac What have the two things got in common? They’re both victim ideologies. You never build anything from victimhood.”

This leads us to immigration. Blair argues that record levels of net legal migration — 745,000 people in the year to December 2022, 672,000 in the year to last June — are an indicator that Britain remains a relatively attractive place to live. “It’s a great test of a country — are people trying to get into it or out of it?” he says.

But illegal immigration is also soaring. More than 4,600 people made the dangerous Channel crossing in small boats in the first quarter of the year — the highest number ever recorded. There were 29,437 arrivals last year, down from a record of 45,774 in 2022.

Blair is not a fan of the Conservatives’ plan to fly illegal immigrants to Rwanda, which is being batted between the Commons and the House of Lords. “Politics works when policy comes first and politics comes second,” he says. “When you ask what’s the right answer to a problem and then you shape the politics around that. Part of the reason Britain is in the difficulty it’s in is politics have come first and policies second. Immigration is a classic example. One of the reasons the Rwanda boats thing has been chosen [by the government] is it gives you a huge political row. But for what? If you actually want to deal with immigration, deal with people’s right to be here.”

The answer? We’re back to ID cards — endorsed afresh this month by Lord Blunkett, who as home secretary was instrumental in New Labour’s original attempt to bring them in. This time they would be digital, not the plastic kind that so offended opponents such as a young Liberal Democrat MP called Nick Clegg in the mid-Noughties. Blair points out that migrants who clamber ashore can easily slip into the black economy. “The problem is that once you are here, it’s very difficult to track people,” he says. “So at any one time, you’ve probably got 750,000 [or] maybe even a million people here without permission. They can come in as students, they can come travelling to Britain on a tourist visa and they can stay. My thing is nothing to do with Rwanda, per se. It’s just I don’t know how many people you’re really going to be able to deal with through that.”

Blair gets frustrated with the civil liberties opposition to ID cards — the idea that they would somehow put us on a slippery slope towards a Chinese-style social credits system. “People give more information to Amazon and Netflix and the local supermarket than they do to the government — it’s a ridiculous argument,” he says. “If you’re in Singapore you have the Singpass, which gives you everything. You get your passport, you have your health records all in one place. Anyone who interacts with the health service, you’re often chasing your health records around different bits of the system. You go and see another doctor in another part of the country, they can’t pull up all your records.”

Blair, whose father chaired the Durham Conservative Association, could be described as politically ecumenical. He co-authored his reports on AI and digital IDs with Lord Hague of Richmond. He mentions that he is seeing a serving Tory minister after our meeting. So his dire prognosis for the Conservatives should not be taken as tribal sniping.

“What’s happening now is that essentially 20th-century debates about state versus market and tax and spending — the left used to believe the larger the state, the more just the society, the right used to believe in the market as supreme — people don’t think like that any more,” he says. “Where you’ve got a political system that allows in new entrants easily — let’s say you’ve got proportional representation, or you’ve got the French [presidential] system — all over Europe, traditional parties are getting disrupted. Over here and in America, because of the way our system is, the two political parties are kind of pile-driven into the political landscape. But what happens when you’ve got that situation is that the disruption happens within the political party The truth is the Conservative Party is no longer a traditional Conservative Party. The Labour Party’s in a state of flux.”

Just two topics make the world king turn coy. One is whether the Democrats will stand by an increasingly wobbly Joe Biden as his rematch with Donald Trump looms. “That’s one thing I’m not getting into,” Blair says, chuckling. “I have enough problems trying to sort out politics here.”

The other is Israel. Blair keeps an office there and takes “a very keen interest in it, but behind the scenes”. He was in the White House three and a half years ago when the Abraham Accords were signed, normalising diplomatic relations between Israel and the UAE and Bahrain.

Blair’s government suspended some arms sales to Israel in 2002 over its military incursion into the West Bank. He says he has been speaking to Binyamin Netanyahu, but declines to say much about the deepening humanitarian crisis in Gaza, where seven aid workers — including three Britons — were killed in an Israeli airstrike this month. “It’s the most difficult problem any Israeli prime minister has had to face,” Blair says of the situation since the October 7 atrocities. “I don’t talk about a lot publicly, until I’m ready to talk about it.”

To spend an hour with the man dubbed “The Master” by a young George Osborne is to be reminded of his superlative communication skills. Even bland generalities are expressed so persuasively that you can find yourself nodding along in instinctive agreement. But Blair comes out with a particular bit of charming sophistry that is immediately unbelievable.

“The most important thing is to wake up every morning with a sense of purpose and go to bed at night counting your blessings,” he says. “If I didn’t have a sense of purpose, I don’t know what I’d do, really. Sit around and drink all day or something.”

Tony Blair, parked in front of Songs of Praise with a bottle of Château Screwtop? I don’t think so.