A high-profile resignation in Britain's main opposition Labour over its handling of multiple anti-Semitism allegations pitched the party into crisis on Thursday on an issue that has stalked its hard-left leader Jeremy Corbyn ever since he took charge.
The resignation of Christine Shawcroft, the official in charge of cracking down on anti-Semitism in the party, was the latest twist in a row that came to a head this week when Jewish campaigners held an unprecedented protest outside parliament.
Scores of party members have been suspended, expelled or forced to resign for making anti-Semitic statements since Corbyn became party leader in 2015, but he and his far-left supporters have been accused of a "complacent" approach to the problem.
Corbyn started the week with an apology for "pockets" of anti-Semitism in the party that was quickly rebuffed by British Jewish leaders who accused him of siding with anti-Semites.
They called a protest on Monday, saying "enough is enough".
Around 500 demonstrators gathered outside the parliament in London, where they were met with counter-protests by Jewish Corbyn supporters, leading to heated exchanges and minor physical confrontations.
Members of the main rally shouted "shame on you" and "scum" at the group of around 50 Corbyn supporters, who claim that the accusations levelled at Labour are politically motivated.
Allegations of anti-Semitism have been a problem for veteran socialist Corbyn ever since his improbable leadership win.
Immediately after the victory he was forced on the defensive for having once referred to Hamas and Hezbollah -- militant groups that deny Israel's right to exist -- as "friends" at a discussion about the prospects for peace in the Middle East.
He was not helped a year later when one of his key allies, former London mayor Ken Livingstone, made a series of comments linking Hitler to Zionism that caused global condemnation.
Livingstone has since been suspended from the party indefinitely.
Another blow came when award-winning film director Ken Loach, a major Corbyn supporter, made controversial comments about the Holocaust in a BBC interview in September 2017.
Asked if Holocaust denial was acceptable, Loach said: "History is for all of us to discuss. All history is our common heritage to discuss and analyse. The founding of the State of Israel, for example, based on ethnic cleansing, is there for us to discuss."
Loach later clarified his comments saying that the Holocaust was "as real a historical event as World War II itself and not to be challenged".
The latest crisis began last week when Corbyn was forced to apologise over a Facebook post he wrote in 2012 in support of a street artist whose mural, featuring clear anti-Semitic symbolism, was due to be removed following complaints.
Robert Shrimsley, editorial director of the Financial Times, wrote that Corbyn and his supporters had "ignored and denied" anti-Semitism in the party until last week.
"Mr Corbyn can still fix this issue. But he is going to have to start to look as though he wants to," he wrote.
The leftist Guardian also focused its criticism on Corbyn.
"Jeremy Corbyn does not lead an anti-Semitic party. But he is too complacent and reactive to a vile issue that threatens his moral authority," it said.
Corbyn made a latest attempt to quell the crisis by giving a long interview to Jewish News on Thursday.
In the interview, Corbyn revealed that there had been 300 internal party referrals for anti-Semitism since 2015.
Of that number, he said 150 were either expelled or resigned.
"I'm not an anti-Semite in any way, never have been, never will be," he said, defending his record on tackling the problem.
But the paper was unconvinced, saying in a front-page headline: "We gave Jeremy Corbyn a chance to finally repair the damage. But his answers were simply... NOT GOOD ENOUGH".