I am a Muslim, so that makes me suspect. I'm also a leftie, so doubly suspect. Add to that the conclusive proof: I have often criticised Israeli policies in newspapers, on radio and TV. This is exactly what an anti-Semite looks like in our times. The more you deny it, the more you 'prove' your accusers are right.

This is worse than McCarthyism, because you are not even interrogated or presented with spurious evidence. ( At this point I start to feel silent terror. Am I allowed to say this? Will I, once again, be labelled anti-Semitic? How do I persuade them I am not?)

But they do say we live in a society where freedom of speech is sacrosanct. I think it is important and perfectly possible to discuss the topic without causing offence to this side or that. The Jewish Chronicle, the Jewish Board of Deputies, Friends of Israel in Parliament, sundry commentators and activists and, increasingly, politicians of all parties, fear anti-Semitism is on the rise.

They are right to be concerned. But some of them now knowingly shield Israel from opprobrium by averring that all critics of that state are veiled anti-Semites. That is plainly wrong and unfair.

Those who deny anti-Semitism are just as iniquitous. Thousands of British Muslims who claim to support Palestinians are, in truth, deeply anti-Semitic. Palestine gives them a useful alibi, a respectable way to vent their ethnic hatred. The same is true of a vast number of other British citizens from right to left. I recently asked why habitual protesters had not gathered outside the Russian Embassy to damn the inhumane assaults on Syria. 'What if Israel was doing this? I asked. That provoked much hot rage and abuse. Overnight I became a 'Jew lover'.

Last week the cross party home affairs committee, made up of reasonable and honourable MPs, produced a report that stated anti-Semitism is spreading across the UK and in all political parties. The committee reproved Corbyn and his supporters most of all. Tim Loughton, the acting chair of the committee, said Corbyn was 'in denial'.

Corbyn is not Hitler or Idi Amin. Labour colleagues who detest him are using this report to bring him down.

A media blizzard followed. Shami Chakrabarti was denounced because in her report on anti-Semitism in the Labour party she did not savage the leader or his supporters. Soon after she was then given a peerage and front bench job. The campaigner, once so admired for her relentless fight for justice and human rights, is today traduced as a corrupt operator. (I think the timing of the peerage was a hostage to fortune, but Chakrabarti is a woman of integrity. I know that because I know her)

Corbyn should have taken the committee report findings seriously. He failed to do that clearly and cleanly and so the story continues. But again, Corbyn is not Hitler or Idi Amin. Labour colleagues who detest him are using this report to bring him down. Columnists – among them Hugo Rifkind of The Times – are gunning for him again. None of this is edifying. It's as if the nation needs a replacement Guy Fawkes to burn. This year, they are metaphorically burning effigies of Jeremy Corbyn.

It seems to me that all sides have so muddied the waters it has become impossible to examine the issue clearly and dispassionately. It's like stepping into a gaseous swamp, into which you soon sink, unable to see, breathe, or think clearly.

Some things do need to be stated without fear or favour. Israel continues to flout international laws, grab territory illegally, has nuclear weapons that are not inspected and has turned extreme humiliation and violence into state policy. Radical, ruthless Palestinians are responsible for the unending dispute. They aggravate, kill and destroy the peace of Israeli citizens. But Israel is vastly stronger and that is why the world is appalled. That is why so many Jewish activists support the Palestinian cause. They are much ostracised.

Influential writers such as Melanie Phillips, Fredric Raphael and Howard Jacobson have, for a while, been making the case that objections to Israeli policies amount to a 'new anti-Semitism'. That is exactly the same argument made by those for whom criticism of bad Muslims is, in essence, an expression of subtle 'Islamaphobia'. Staunch Zionists and equally staunch Muslim dogmatists, defenders state and faith, have more in common than they care to know. They devalue the principles they hold dear. Not good.

But back to the home affairs committee report and Labour's response. Corbyn should stop dilly-dallying, man up, and confront anti-Semitism in his party. It is there; it's real; it hurts. Hitherto he has sounded too shifty and floppy. But he must also confront the bullies inside and outside parliament who are using slurs of anti-Semitism to stop Labour party members and other Britons from scrutinising and condemning the Zionist state's treatment of Palestinians. None of this is easy. But he was elected leader and now he must prove he understand what leadership entails.

Yasmin Alibhai-Brown is a journalist, columnist, broadcaster and author.