They were 10 words that shook Jeremy Corbyn’s Labour party. This week the party’s ruling body accepted the International Holocaust Remembrance Alliance (IHRA) definition of antisemitism and the accompanying examples in full, including that it can be considered antisemitic to claim the “existence of a state of Israel is a racist endeavour”. This ought to have ended Labour’s summer of madness. Yet it seems that Britain’s political season will begin as the holidays started: with finger-jabbing rows about how racist or not the Labour leader is. Some Labour MPs say Mr Corbyn can’t solve this crisis because he is the problem. Mr Corbyn has made mistakes, and he has apologised for some of these. British Jews’ trust in his Labour party is at a historic low. Some of the criticism is fair, some of it is unfair. At the heart of the problem is that two issues are being conflated: one is the crisis in the Holy Land; the other is the safety and security of Jews in the UK.

The Labour party is not antisemitic, but there are pockets of Jew-hatred within it. Online these have festered, often unchecked. Bigotry cannot be acceptable among Labour members. The defence of anti-Zionism cannot be invoked when using antisemitic tropes. Mr Corbyn must stop supporters turning a denial of antisemitism into a kind of leftwing principle. His ally Peter Willsman made unacceptable remarks and is unfit, at present, to sit in judgment on others on the NEC. There is a kneejerk and wrong response by sections of the left to see a factional attack behind every claim of antisemitism. The fear and anxiety felt by many British Jews is not to be belittled. Labour must be a reliable ally in fighting prejudice and Mr Corbyn’s party ought to be a protective, not hostile, environment.

Mr Corbyn had grounds not to implement the text in full. Six nations that have implemented the IHRA are engaged in outright glorification of Nazi collaborators and Holocaust distortion if not denial. It was deemed flawed by a parliamentary select committee in 2016, and has ended up as a tool, according to its author, to curtail free speech in the United States. This is a real concern. Next month one London council will debate whether or not to ban supporters of the Boycott, Divestment and Sanctions movement from using its facilities, because BDS allegedly fits the IHRA definition of antisemitism. Mr Corbyn does not support the boycott movement, but he wants to protect the right not only to criticise but to organise around that criticism.

The Labour leader is staunchly pro-Palestinian. The Palestinian narrative of dispossession and expulsion could be stifled, if not outlawed, by interpretations of the IHRA. Punishing political speech would stir more discord. If Jews have a right to define what oppresses them then Palestinians should also have the same right. Standing up for the Palestinian cause does not make one an antisemite and it is crucial that a space for Palestinians to talk about their experience of loss is maintained. However, in appearing reluctant to accept the full IHRA text, Mr Corbyn confirmed to some British Jews that he did not have their welfare at heart. He ought to reflect on this and seek ways to reach out, with humility, to the British Jewish community. He does not need to take lectures from the Conservative party – its code of conduct does not expressly mention antisemitism once, let alone define it. Mr Corbyn pledged that he would root out antisemites from Labour. He must make good, demonstratively, on this promise. It’s entirely possible to do this while retaining his principles on Palestine.