Who would have thought that antisemitism – and the way it has infected and toxified the Labour party – would become a dominant theme of an election campaign?

The party’s problems over this are wholly self-inflicted. It isn’t just because in one interview Jeremy Corbyn refused four times to apologise for his abject failure to tackle the issue, straight after refusing to acknowledge the trope of “Rothschild Zionist” conspiracy as racist against Jews. But these serve as good metaphors for the wider issue.

The Jewish Labour Movement – a founding affiliate of the party nearly a century ago – has for the first time effectively downed tools for the election, campaigning only for exceptional candidates who have been the best of allies to us in our fight against the party’s anti-Jewish racism. Our members concluded a while ago that Corbyn isn’t fit to be prime minister. Over the past four years, we’ve told the party until we are blue in the face that it is failing its Jewish members and tolerating antisemitism.

But we’ve been met with obfuscation, denial and delay, so we referred the party to the Equalities and Human Rights Commission to investigate it for institutional antisemitism.

Our final summary submission has been leaked to the media. We’ve only ever sought to work with the EHRC, so this is far from what we wanted to see happen. But to be clear: what has been reported on so far is the real deal. When we conclude that the Labour party is no longer a safe space for Jewish people, this is based on the testimonies of former staff, Labour party members and officials.

Brave whistleblowers, who were hypocritically targeted by party briefing and legal action, demonstrated the scale and depth of the problem.

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The witness statements from members show that the all-pervading culture of antisemitism that is present in all parts of the party; local party meetings, conferences, online forums, the disciplinary processes and its officials.

The testimony from current officials lays bare that the scale of the problem, as reported by the party, is inaccurate. There are no credible figures because the backlog of cases are not reported. Claims made by Corbyn that all individuals subject to complaint have been suspended or expelled are untrue.

Perhaps the most depressing aspect of this campaign has been the arms race of which party is the most racist

This isn’t just our political commentary. The serious status of the EHRC’s investigation means that it can – and has – deployed its legal powers of compulsion. Our submission is a legal document; the evidence in it is made up of sworn statements by witnesses.

Whatever way you want to spin it, more than 70 whistleblowers aren’t all effectively lying on oath because they want to smear Corbyn, No, they came forward because – like us – they joined the party because they lived its values of equality, tolerance and antiracism. When that turned rotten, when it became a greater priority to protect your political allies than kick bigots out, those whistleblowers, like us, knew they had to act.

Perhaps the most depressing aspect of this campaign has been the arms race of which party is the most racist. The Tories undoubtedly have a deep problem with Islamophobia. People should be aware of that.

But any Labour member who doesn’t think the party shouldn’t be better than the Tories on this issue and should hold themselves to a higher moral standard really needs to check their values. Maybe you think it doesn’t matter, compared with Brexit and the NHS. Maybe you think that as long as the Tories are as bad, it’s a score draw.

But our legal submission makes it clear that Labour’s antisemitism is so all-pervading that, to this day, the party has so actively resisted changing for the better, you can’t pretend it’s all a smear.

The only question remains: what do my fellow members want to do about it? We can’t take a rain check on calling out antisemitism just because the timing is inconvenient. Corbyn and his team have had more than enough time to sort it out. They decided not to.

While we wait for the EHRC to complete its investigation, the judgment on Corbyn’s choice lies with the people.

• Mike Katz is the chair of the Jewish Labour Movement