Labour deputy leader Tom Watson, who has been a vocal critic of the party’s failure to deal with antisemitism, has resigned as an MP.
Mr Watson announced he was quitting late on Wednesday in a letter to Jeremy Corbyn.
The MP for West Bromwich East, who in his time as deputy leader challenged Mr Corbyn over issues including Brexit and the rise of antisemitism in the party, said he would not be seeking to retain his seat in next month’s election.
His letter did not raise antisemtism as a reason for his resignation - it instead claimed he was standing down for “personal, not political” reasons and that he wanted to “start a different kind of life.”
Mr Watson said he would continue to campaign for the party ahead of the election.
He said: “I’m as committed to Labour as ever. I will spend this election fighting for brilliant Labour candidates and a better future for our country.”
Mr Watson, who has been thought of as one the key allies of Jews in party, is a member of Labour Friends of Israel and argued against Labour’s initial refusal to adopt the full International Holocaust Remembrance Alliance (IHRA) definition of antisemitism.
At the time Mr Watson said the party risked descending into “eternal shame” if it did not adpot the definition of antisemitism.
Earlier this year, he poured scorn on Mr Corbyn's claim to be dealing with the scourge of Jew-hate in his party, telling the JC: "It's no good just condemning something - it's about actually doing something about it."
Speaking out after his speech as deputy leader was cancelled at Labour's conference, Mr Watson said his party still had "a very long way to go" before restoring "anything near trust with the Jewish community."
He also hit out at the "sickening intimidation" of Jewish delegates and other allies at the entrance to the Brighton conference venue by far-left activists who held up antisemitic cartoons and distributed hate leaflets.
News of his resignation comes as former Labour MP Ian Austin, who resigned from the party in February over antisemitism, said Mr Corbyn was "completely unfit to lead our country".
"I can't believe it has come to this."
— BBC Radio 4 Today (@BBCr4today) November 7, 2019
Ex-Labour, now Independent, MP Ian Austin's emotional appeal for voters to back Boris Johnson over Jeremy Corbyn in the General Election.#r4Today | https://t.co/s6BnQpZL5K | @bbcnickrobinson pic.twitter.com/EpAwl1jGUN
Speaking to the BBC, Mr Austin, who joined the Labour party in his teens, said people should vote conservative to avoid electing Mr Corbyn.
He said: "I can't believe it has come to this."
He told BBC Radio 4’s Today programme: “There’s only two people who are going to be prime minister on December 13. Jeremy Corbyn or Boris Johnson. And I think Jeremy Corbyn is completely unfit to lead our country. Completely unfit to lead the Labour Party.”
He said he would be telling “decent traditional patriotic Labour voters that they should be voting for Boris Johnson at this election”.
He said Mr Corbyn had “spent his entire time in politics working with and defending all sorts of people: extremists and in some cases antisemites and terrorists”.
Jonathan Goldstein, the chair of the Jewish Leadership Council, paid tribute to Mr Austin and his decision to leave the party by saying that as the son of a Holocaust survivor, Mr Austin knows “more than most how dangerous anti-Jewish racism in our politics can be”.
Mr Goldstein said Mr Austin had “done everything he can” to fight racism and it had been “at great personal cost, to be true to himself, his values and what he knows to be right.”
Statement from JLC Chair @jonnysgoldstein on @IanAustin1965's decision not to stand for Parliament again. pic.twitter.com/SxprSP2RvH
— Jewish Leadership Council (@JLC_uk) November 7, 2019