Labour leader Jeremy Corbyn boards a train in Leeds | Jack Taylor/Getty Images Brexit Files Insight Why Brexit is Jeremy Corbyn’s best hope For all his ambivalence about the EU, Brexit now looks like the Labour leader’s best chance of survival.

LONDON — The wounds may now be too deep to stitch. Only Brexit — and self interest — is stopping the Labour party's bleeding.

After months of sustained infighting about anti-Semitism in the party and past actions of Corbyn himself, Labour's ruling body on Tuesday accepted the full definition of anti-Semitism drawn up by the International Holocaust Remembrance Alliance, including all the contemporary examples of Jewish hatred it gives. It also attached a statement emphasizing freedom of expression when discussing Middle Eastern politics.

The Labour leadership hopes that will draw to a close a torrid summer of headlines and ease the pressure on the party. Any respite may prove short-lived though.

Many of the Labour MPs who have called for the full, unqualified IHRA definition to be adopted in the party’s code of conduct will feel vindicated and, perhaps more importantly, encouraged that they can still make a difference within the party’s structures despite Corbyn’s now almost total dominance. That dominance was displayed by the trouncing of the moderates in the election of the full pro-Corbyn slate to the party’s ruling body Monday.

Yet, the wound remains.

When asked whether tensions would now ease, one senior Labour official and Corbyn loyalist replied with a photograph of the mass protest that had gathered outside the party’s headquarters. “I mean … the issue has DEFINITELY exploded,” the official said.

The breakdown in trust between Jewish leaders and the Labour party is now complete. Jonathan Sacks, the U.K.’s former chief rabbi, told the BBC Sunday that Corbyn was “as great a danger as Enoch Powell” in reference to the hard-right Tory MP whose “rivers of blood” speech in 1968 claimed Britain was “heaping up its own funeral pyre” by allowing immigration from the Commonwealth.

Senior Labour MPs say the relationship between Labour and the Jewish community in the U.K. is now irreparable.

So, what next?

Many Labour MPs — some doggedly opposed to Corbyn’s leadership already, others ambivalent before this dispute — remain anguished about their leader’s handling of the issue. A small minority of the party’s MPs have come to the seemingly irreversible conclusion he is an enabler of Jew hate, willingly or not.

Two Labour MPs, Frank Field and John Woodcock, resigned to sit in the House of Commons as independents. Both have been dismissed by Corbyn supporters as cowards, jumping before they were pushed, either because they were facing de-selection by their own local party or disciplinary procedures before the anti-Semitism dispute began.

However, many Labour MPs who oppose Corbyn’s leadership don’t want to put their heads above the parapet because they fear abuse from the Labour leader’s army of online supporters. “They don’t want to become a magnet for abuse,” one prominent anti-Corbyn MP said. “They’d rather lie low, see it out until [Corbyn's] gone.” Another MP said: “They say supportive things in private, but won’t do anything publicly.”

In fact, the biggest obstacle to a full-scale rebellion among anti-Corbyn MPs is not the political vitriol that will come their way should they make a move, but pure political calculation. They do not want to be blamed for sparking an internal battle at a time of national crisis over Brexit.

Despite multiple divisions in the party over Brexit, too, many of Corbyn's most ardent critics on his own backbenches are also the most pro-EU MPs within the party. These MPs fear that splitting the party now risks dividing opposition to Prime Minister Theresa May and potentially pushing Britain toward a hard break with the rest of the European Union.

For all the multiple splits across Labour, exposed all summer long by bitter accusations about anti-Semitism, and despite Corbyn's own lack of enthusiasm for the EU, Brexit now looks like the Labour leader's best chance of survival.

This insight is from POLITICO's Brexit Files newsletter, a daily afternoon digest of the best coverage and analysis of Britain’s decision to leave the EU available to Brexit Pro subscribers. Sign up here.