‘It absolutely breaks my heart to say, but I do not think the Labour party is a safe space for Jewish people any more.” Thus spoke Izzy Lenga, a Labour member interviewed in last week’s Panorama documentary on antisemitism in the party. Her words echo sentiments expressed by many Jewish MPs, members and supporters in recent months, and are a dreadful indictment of Labour’s failure to confront and root out antisemitism within its ranks.

The documentary brought to light fresh allegations about interference from Jeremy Corbyn’s office in disciplinary procedures supposed to be independent of the party’s leadership. It found that, as recently as this spring, 1,000 complaints about antisemitism had yet to be dealt with, and so far only 15 people have been expelled as a result. But the most powerful moments of the programme were in the brave testimony of party members and staff who spoke of their experience of dealing with antisemitism and its impact on their mental health.

Play Video 1:05 Four whistleblowers speak of top Labour aides interfering in antisemitism investigations - video

Before the programme was broadcast, Labour dismissed the whistleblowers – one of whom told the programme he had suicidal thoughts while he was working for the party – as “disaffected former officials” with “political axes to grind”, and threatened to sue them for breaking non-disclosure agreements. As reported in today’s Observer, these whistleblowers are taking legal action against the party leadership for defaming them.

Labour’s official response denied that there was a problem with its disciplinary procedures, and asserted that the rate at which antisemitism cases are being dealt with has increased fourfold, without providing any evidence.

This response marks a new low, but it is not out of character. Corbyn has been under scrutiny for the way his party deals with cases of antisemitism for more than three years: in 2016, the home affairs select committee was damning about Labour’s disciplinary processes. Yet he has failed to get a grip on this, appearing not to care sufficiently to have made it a priority.

Serious questions remain about the lack of action taken against high-profile Corbyn allies accused of antisemitism.

Last month, Chris Williamson MP had the Labour whip reinstated after being suspended for suggesting the party was “too apologetic” about antisemitism, when a panel ruled he should only receive a reprimand (the suspension was reinstated following a backlash from MPs and peers).

Facebook Twitter Pinterest An investigation into Pete Willsman is pending Photograph: Andy Rain/EPA

In May, Pete Willsman was suspended for alleged antisemitism for the second time in 10 months when a recording emerged of him accusing the Israeli embassy of “whipping up” complaints against Labour. The investigation into Willsman is pending and he remains a member of Labour’s national executive committee. This contrasts starkly with the speed with which Alastair Campbell was expelled from the party after saying he didn’t vote Labour in the European elections: it took just two days.

The Equality and Human Rights Commission is conducting a statutory investigation into antisemitism in the party, but it is likely to be months before it reports. Labour must act now. As a minimum, it must introduce an independent disciplinary process that is transparent about the number of complaints it is dealing with, the rate at which they are being processed, and their outcomes.

But reforming processes is not enough: Labour’s antisemitism problem is one of culture, not just procedure. Of course antisemitism is not limited to the left. But the nature of antisemitic tropes that paint Jewish people as a malign, controlling influence of the world means that some on the left have been particularly susceptible, even as they loudly proclaim themselves anti-racists. And in among his vows that Labour stands against “all forms of racism”, and the implication that Labour’s problems with antisemitism are merely a product of the fact that it exists in society at large, Corbyn has failed to acknowledge this. The chief rabbi, Ephraim Mirvis, last week said that the Labour leadership was directly complicit in the scourge of antisemitism. It is to Labour’s great shame that he is right.