There is a “severe” antisemitism problem within Labour, Chief Rabbi Ephraim Mirvis has claimed in his first public comments on the crisis engulfing the party.

In a wide-ranging article explaining his concerns about the allegations and comments of recent weeks, Rabbi Mirvis attacked those who, he said, had tried to separate Zionism and Judaism.

It would be the “worst of mistakes”, he said, to treat the problem as a “political attack which requires a political solution”.

Rabbi Mirvis said he hoped the independent inquiry led by Shami Chakrabarti would deliver on Jeremy Corbyn’s pledge for the party not to tolerate antisemitism in any form.

But he warned: “If this inquiry turns out to be no more than a sticking plaster, designed to placate and diffuse until after the elections this week, the problem will surely get worse and not better.”

Writing in the Telegraph, Rabbi Mirvis said it was “astonishing” that those on the hard-left of British politics were “presuming to define the relationship between Judaism and Zionism despite themselves being neither Jews nor Zionists.

“The likes of Ken Livingstone and Malia Bouattia claim that Zionism is separate from Judaism as a faith; that it is purely political; that it is expansionist, colonialist and imperialist.

“It is unclear why these people feel qualified to provide such an analysis of one of the axioms of Jewish belief. But let me be very clear. Their claims are a fiction. They are a wilful distortion of a noble and integral part of Judaism.”

Directly addressing those who had sought to “redefine…vilify…and delegitimise” Zionism, Rabbi Mirvis wrote: “Be under no illusions – you are deeply insulting not only the Jewish community but countless others who instinctively reject the politics of distortion and demonisation.

“To those who so eagerly reach for a vicious Holocaust reference in order to exact the maximum amount of pain and offence upon ‘Zionists’, I say: You are spreading that ancient and insidious virus of antisemitism.”

But the Chief Rabbi said he was also optimistic about the future and had drawn “a great deal of comfort from the very strong response that this sorry affair has elicited”.