Peter Thiel, the co-founder of PayPal and Palantir Technologies, is stepping down from the board of Facebook’s parent company, Meta, after 17 years.

Thiel, Facebook’s longest-serving board member and a major donor to the Republican party, plans to focus on backing Donald Trump’s allies in the November midterm elections, according to the New York Times. He recently donated $10m each to the Senate campaigns of Blake Masters, who is running for a seat in Arizona, and JD Vance, who is running in Ohio. Masters is the chief operating officer of Thiel’s family office and Vance used to work at one of Thiel’s venture funds.

Thiel has long been a controversial figure on Facebook’s 10-person board, particularly as one of a few major tech figures who vocally supported Trump. Thiel, who donated millions of dollars to Trump’s campaign and served on the ex-president’s transition team, was seen by critics as a part of the reason Facebook did not take down Trump’s posts that violated its community standards. Thiel is a close confidant of Zuckerberg’s. He accompanied him to a private dinner with Trump in 2019 and has successfully advocated he withstand pressure to take political speech and ads off the platform.

But recently he has publicly criticized Facebook’s content moderation decisions, saying he’d “take QAnon and Pizzagate conspiracy theories any day over a Ministry of Truth”.

Thiel joined Facebook’s board in 2005, a year after the company was founded and seven years before its made its debut on Wall Street. The company said on Monday that he would stay on until Meta’s next shareholder meeting later this year, where he would not stand for re-election.

“Peter has been a valuable member of our board and I’m deeply grateful for everything he’s done for our company,” said Mark Zuckerberg, chief executive of Meta, in a statement. “Peter is truly an original thinker who you can bring your hardest problems and get unique suggestions.”

In a statement on Monday, Thiel called Zuckerberg “one of the great entrepreneurs of our time” and praised his “intelligence, energy and conscientiousness”.

The Associated Press and Reuters contributed reporting.