This letter originally appeared in The Observer on 14th July 2019.

Over the past four years, we have watched the unchecked spread of vicious antisemitism – anti-Jewish racism – in the Labour party with bewilderment and disgust – all the more so since we respected Labour’s long previous history of fighting racism, and its many brave and decent members.

As accusations of antisemitism became too insistent to ignore, the Labour leadership set out to change the narrative from hate to housekeeping. Yes, there were minor issues, the Labour leadership conceded, but those related only to the time it was taking to identify the few actual or seeming antisemites in the party and the occasionally flawed system of dealing with them. Otherwise, all suggestions that racist hate against Jews was becoming endemic to Labour were mendacious, mischievous and malign.

Now, after the BBC’s Panorama programme, we can see for ourselves what is and isn’t false. The extent of Labour’s antisemitism, the degree to which it has been protected, sanctioned and propagated by the leadership faction, can brook no further denial; the labyrinthine attempts to deflect attention from the problem and discredit officials supposedly charged with identifying and rooting it out, are now laid bare. There is nowhere left for the Labour leadership to hide. It is clear this is not just about Jeremy Corbyn but the pernicious world view of a faction that has – temporarily, we hope – taken control of Labour.

But yet again, rather than seize this moment to face up to the racism at its heart, the Labour leadership remains determined to go on piously protesting its innocence, rejecting the message and blaming the messenger. People prepared to bear witness have been forced to sign gagging orders; those who have dared to speak out have been bullied, defamed, and stigmatised as dishonest and disloyal. What drives them, the leadership insists, is nothing other than political or personal disaffection. We are where we were before. Whistleblowers would be heroes to any other Labour party; to this Labour party they are traitors. Regrettable double standards are therefore operating, where Labour is keen to support whistleblowers elsewhere but not in its own house.

In our view, those whistleblowers and Labour members who could no longer stomach what was happening in a party they loved, and were in some cases driven to the point of nervous breakdown by it, have shown a rare moral courage and decency that belongs in a great tradition, and gives us hope. In the meantime, trust between Corbyn’s Labour and most Jews in Britain appears to be fractured beyond repair. The very fact that Labour is, like the BNP before it, being statutorily investigated by the Equality and Human Rights Commission for racism is not a matter of housekeeping, but a taint of international, historic shame.

There are procedures that could take the heat out of this – a fully independent complaints body, for example, over which Corbyn and his inner circle exert no covert influence. Not with the aim of shuffling off blame, but in order, finally, that the party will honestly own up to what can no longer be filed away in a folder. After Panorama, damage limitation should not be the first priority for Labour. Draining the antisemitism that lies like a pool of poison in the party’s soul is. Now, nothing else will do.

Howard Jacobson, Simon Sebag Montefiore, Sir Simon Schama, Neil Blair, Tracy-Ann Oberman, Rabbi Julia Neuberger