The leaders of two influential labor unions have left the Democratic National Committee, with one of them citing disagreements with Chair Ken Martin, marking the latest sign of internal discord in the party.

Randi Weingarten, president of the American Federation of Teachers, and Lee Saunders, president of the American Federation of State, County and Municipal Employees, recently declined offers to stay on as at-large members of the DNC. Both supported a rival to Martin for party chair this year, and Martin removed both from the DNC’s Rules and Bylaws Committee.

Their letters explaining the decisions, obtained by The Washington Post and first reported by The New York Times, became public as infighting at the DNC has spilled into the open.

Weingarten suggested she had concerns about the party’s direction in a letter to Martin declining to continue as an at-large member, a role she has held for decades.

“While I am proud to be a Democrat, I appear to be out of step with the leadership you are forging, and I do not want to be the one who keeps questioning why we are not enlarging our tent and actively trying to engage more and more of our communities,” Weingarten wrote in her letter to Martin, obtained by The Washington Post.

The letter, dated June 5, did not elaborate on her reasons for leaving. Weingarten had served on the Rules and Bylaws Committee since 2009. She was vocally supportive of David Hogg, the Gen Z activist who departed his role as DNC vice chair last week after a messy dispute with Martin and other party officials.

A person close to the DNC, who spoke on the condition of anonymity to discuss an internal issue, pointed to Weingarten’s support for a rival candidate for DNC chair: former Wisconsin Democratic Party chair Ben Wikler. Since Wikler’s loss, Weingarten has “been on the other side of the fence as Ken,” making her exit unsurprising, this person said.

Saunders wrote in a May 27 letter to Martin that “public service workers are facing unprecedented attacks,” that this “moment demands unwavering focus” and that “in that spirit, and with deep respect, I must decline your nomination to the DNC.”

“This decision reflects our full commitment to fighting the battles ahead,” Saunders added.

Hogg, the young activist elected DNC vice chair this year, blindsided other party officials with his plans to back through his separate political organization young liberals in primaries against a select group of “out-of-touch, ineffective” Democratic lawmakers. He tapped into a broad sentiment that Democrats had allowed some of their oldest leaders to linger too long in office, but drew pushback from colleagues who said party officers should stay out of primaries.

The open conflict was so frustrating to Martin that he privately told Hogg he had “destroyed any chance I have to show the leadership that I need to” - comments that leaked to Politico last weekend and led several DNC officers to publicly accuse Hogg of secretly recording. Hogg denied it.

Hogg announced Wednesday he would step down from his vice chair role after DNC members voted to redo the vice chair election.