Three weeks ago, we took the unprecedented decision to call upon our Jewish community to go to Westminster and publicly protest against antisemitism in the Labour party. In truth, 72 hours before the protest, we had not seriously considered such a thing, but over the quiet contemplation of the Jewish Sabbath, something snapped in both of us, part of the sudden mood swing we felt in our respective synagogues and around our Friday night dinner tables.

Almost every day of the previous week, there had been some story relating to Labour’s poor handling of the antisemitism allegations that have dogged the party since February 2016. The last straw came when it emerged that Corbyn himself had sought to defend a mural that he has subsequently acknowledged to have been antisemitic.

With just 24 hours’ notice, our protest was attended by up to 2,000 people from all sections of the Jewish community, and beyond. The mood was more of bemusement, surprise and shock than anger. Bemused individuals who had never been to a protest were wondering what you are supposed to do once you get to one. Surprise that so many had turned up at short notice, despite pressing Passover preparations. Above all, absolute shock that it had come to this.

When people accuse the protesters of being anti-Labour, they could not be more wrong. Many of those who came to the protest identify deeply with Labour and that is why they feel so betrayed. From the platform, courageous Labour MPs spoke with great pain, honesty and integrity about the problem. We knew, as did most of the crowd, the huge risk that these MPs were taking for being there. It is these MPs and many other councillors and members who are now the most vital opponents of antisemitism. Inevitably, the MPs are now facing a perverse backlash for opposing antisemitism and for caring about their party. Corbyn’s leadership in defence of them will now be a crucial component of his promised commitment to combating antisemitism.

The stages of this saga included: the resignation of the president of the Oxford University Labour club over antisemitism concerns; the buried Labour students’ inquiry into it; Baroness Royall’s half-buried inquiry; the suspension of the MP Naz Shah (who exceptionally sought to understand antisemitism and make good); Ken Livingstone’s repeated outbursts; Shami Chakrabarti’s compromised inquiry; Labour party conferences; and too many disciplinary cases to note, many with inexplicably lenient outcomes.

It is an exhausting list, but it is nowhere near exhaustive. Each twist and turn has led only to fiercer denunciations of our organisations and our mainstream Jewish community. Above all, we are accused of “smearing” Corbyn. The shadow home secretary, Diane Abbott, who has herself faced unacceptable racism and so should be a natural ally in this fight, is among those who have made the charge.

We are not merely being denied the most basic principle of anti-racist behaviour – solidarity – but are viciously accused of smears, of dirty tricks, of lies. Our community has seen the havoc wreaked by antisemitism upon European Jewish communities post-2000, but there are many who consider themselves to be on the progressive left who have never shown an ounce of pity for such things, not even with French Jews fleeing in their thousands to Israel, London and North America.

These people claim to be “critical” (not “obsessively hateful”) of Israel, but opposed to antisemitism. If that is the case, why are Jewish concerns not merely ignored but so passionately attacked?

There is, however, an important solution to this and Corbyn has already said it in his letter of reply to us, a reply that did not duck our original open letter to him. Corbyn’s letter laid out a recognition of our concerns and of the specificities of leftwing antisemitism. It gave us the grounds to organise a meeting with him to try to build mutual trust and to attempt a constructive conversation that diminishes Labour antisemitism rather than worsens it. It should deal with issues of leadership, of education, ensuring an effective, transparent and just disciplinary process and tackling a culture of “victim-blaming” that has severely compounded matters.

That meeting is now agreed for 24 April. Last month’s protest was a necessary moment of catharsis, as painful for Labour as it was for our community, but we cannot now return to “business as usual”. We need this to be a genuine turning point and will do everything we can to make it so. We can achieve this together if Corbyn can fulfil his pledge to be our “militant ally” in the fight against antisemitism and demonstrate his understanding that what is now needed is firm action and not just words.

Jonathan Goldstein is chair of the Jewish Leadership Council and Jonathan Arkush is president of the Board of Deputies of British Jews