Jeremy Corbyn, the socialist leader of Britain’s Labour Party, announced Friday that he will resign as leader after his party’s historic defeat at the hands of prime minister Boris Johnson’s Tories.

Corbyn called it a “very disappointing” night after only 203 of Parliament’s 650 seats fell to Labour members, the worst electoral result for the party since 1935. While he has vowed not to lead the party through another election, Corbyn said he will retain his seat during a “process of reflection.”

“I will not lead the party in any future general-election campaign,” Corbyn said. “I will discuss with our party to ensure there is a process now of reflection on this result and on the policies that the party will take going forward.”

“I will lead the party during that period to ensure that the discussion takes place as we move on into the future,” he added.

Even some members of his own party pressured Corbyn, 70, to not only step down as party leader but to resign entirely due to the loss, which they claim resulted largely from his failed leadership.

“Corbyn talking about a period of reflection. I’ve reflected. You failed. Please stand down,” read a tweet from MP Margaret Hodge, a Labour member who kept her London seat.

Meanwhile, Prime Minister Boris Johnson said Conservatives were expected to win 357 seats, the best showing for conservatives since Margaret Thatcher captured a third term in 1987.

“Looking like a big win for Boris in the U.K.!” President Trump wrote on Twitter.

The United Kingdom elections were roiled by debate over Brexit, the 2016 referendum for Britain to leave the European Union. Areas that traditionally elect Labour Party representatives in northern England, the Midlands, and Wales flipped to support the Conservatives Thursday night.

“Brexit has so polarised and divided debate in this country, it has overridden so much of a normal political debate,” Corbyn said. “I recognize that has contributed to the results that the Labour Party has received this evening all across this country.”

While the question of Brexit loomed large over the election, Corbyn’s perceived ties to extremists also likely hurt his party’s chances. He was routinely criticized throughout the election over sympathetic statements he’s made about Islamic terrorist groups Hezbollah and Hamas, as well as for his ties to the IRA. He was also pilloried for failing to adequately address growing anti-semitism within Labour’s ranks.