Jeremy Corbyn is not known to sit in silence: to confront the controversial has been part of his mission since the day he entered the political fray. It was by giving voice and action to his convictions that he has remained so often on the right side of history; it was his decades of campaigning that provided the framework for Labour’s progressive platform today. It’s his resolve that inspired me and hundreds of thousands of others to join a movement, but I fear that today it’s being hidden away.

On antisemitism, Labour needs strong and decisive leadership. Not because it’s rampant in the party, but because it has become a distraction that is refusing to go away. The realty is that there are a smattering of Labour members among the half a million who are explicitly antisemitic, and a small yet vocal minority who are blind to the prejudice that is very much there.

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Committed, socialist, Jewish Labour members have attempted to navigate the complexities of the situation: we have had to face some in our own religious community who have objected to our support for Labour; we have opposed those using the situation to try to harm Corbyn’s leadership. We have also tried hard to educate those who have not understood the more subtle strains of antisemitism, such as the Rothschilds conspiracies and the Jewish-controlled media: being progressive means accepting there is a journey of education we all undertake.

There comes a point, however, where people can no longer be given the benefit of the doubt. Those who continue to peddle antisemitism are already being booted out of the party – but that process must be faster. Those who refuse to see it, such as Peter Willsman, must accept they are wrong if they are to remain.

The basis for this blindness is obvious – a siege mentality that has overtaken elements of Labour. It’s not hard to understand why some Corbyn supporters feel afraid to concede there is a problem: it is a movement that is perpetually under attack. From the Czech spy drivel earlier this year to whether Corbyn bowed properly at the Cenotaph, there are those within Labour’s ranks and outside of it who have made it their mission to destabilise his leadership at all costs. And many members feel that they are being tarnished as antisemites when it’s simply not the case.

But it is time to come out of the bunker and hold our hands up – there is, however limited, a problem, and it’s Jeremy Corbyn himself who has to make this clear.

There are short-term actions that can and must be taken: Corbyn must distance himself from the insensitive comments made by Willsman, however painful it might at first seem. However well-meaning, the attempt by Labour to adapt the International Holocaust Remembrance Alliance’s definition of antisemitism into a more practical document has to be halted. That’s despite the fact many Jewish members, myself included, believe it needs to be addressed. We must recognise that as it stands the trust between British Jewry and the Labour party just isn’t there.

Play Video 0:52 Peter Willsman dismisses Labour antisemitism claims - audio

The most urgent, however, is for Corbyn to break his silence, and speak directly to the group of his supporters who are dismissing all incidents of antisemitism in Labour as lies in his name.

Corbyn has vocally condemned antisemitism before, and made it clear that Labour will not tolerate it. But what is required now is a more reflective, self-critical analysis. Just because antisemitic sentiments may be expressed at lower levels in Labour than in other political parties, it doesn’t mean that it isn’t a problem that should be addressed. Just because the rampant Islamophobia plaguing the Conservative party gets far less airtime than it warrants doesn’t mean antisemitism in Labour doesn’t exist. Corbyn needs to explain that while Labour is no hotbed for antisemitism – far from it – admitting that it does exist, and taking that seriously, is no concession to those who so desperately wish to do him harm. It would only strengthen him.

Corbyn needs to say firmly that responding to antisemitism with conspiracies, a rant about Israel, or anything other than a commitment to fighting it is unacceptable. If you do so Labour is no longer a place for you, and you are not his friend.

John McDonnell is already showing the necessary contrition, visibly pained by the situation. Momentum has taken bold action and withdrawn its support from Willsman (the backlash from those who see that as capitulation is already under way). But Jon Lansman understands this is vital, however uncomfortable. “Although it’s painful, we have to take action on this and lead by example,” he tells me. “Labour is an antiracist party, but the perception among the Jewish community is that we are not taking antisemitism seriously and there is a distressing lack of trust.”

I understand why Corbyn has waited quietly – there are no doubt those around him who believe he should remain locked in the bunker to weather the storm. Today, though, I’m appealing directly to my party’s leader – without whom this problem won’t go away. To risk alienating some of those who have long stood by him – advisers and supporters – won’t be easy. It may feel disloyal, or as if he is throwing those who have shown loyalty under the bus. But the best chance we have of quelling this is for Corbyn himself to guide his supporters. He can’t be accused of being a traitor to himself.

• Michael Segalov is the news editor at Huck magazine and a freelance journalist