UNION chief Len McCluskey has issued a thinly-veiled threat that centrist “Corbyn-hater” MPs could face deselection over what he suggested was a campaign to smear the Labour leader in the party’s anti-Semitism row.

But the leader of Unite, Labour’s largest donor, was in turn accused of undermining Mr Corbyn’s efforts to tackle anti-Semitism.

Mr McCluskey’s intervention, made in an article for the New Statesman magazine, will do little to calm the atmosphere of recrimination within the party; indeed, it is likely to exacerbate it.

Pulling no punches, the union leader accused MPs on Labour's centrist wing of "working overtime, trying to present the Labour Party as a morass of misogyny, anti-Semitism and bullying".

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While stressing his own opposition to anti-Semitism, he accused "promiscuous critics" like MPs Chris Leslie, Neil Coyle, John Woodcock, Wes Streeting and Ian Austin of "polluting" the leader's efforts to tackle the problem.

"I look with disgust at the behaviour of the Corbyn-hater MPs, who join forces with the most reactionary elements of the media Establishment and I understand why there is a growing demand for mandatory reselection," declared Mr McCluskey.

His comments came a week after a series of Labour MPs made emotive statements in the House of Commons about their own experiences of anti-Jewish prejudice in the party.

The Unite leader said: "To watch as these so-called social democrats tried to demean and attack, in front of our enemy, a decent and honourable man who has fought racism and anti-Semitism all his life and who has breathed life and hope back into the hearts of millions, especially the young, made my stomach churn.”

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He added:"To see Tory MPs cheer and applaud them was shameful."

But Mr Streeting. The MP for Ilford North in London, hit back, saying: "I've said it before and I'll say it again: no abuse, intimidation or threats of deselection will prevent me from voicing the concerns of my Jewish constituents about anti-Semitism in the Labour Party."

Mr Coyle, who represents Bermondsey and Old Southwark, tweeted: "Jeremy says anti-Semitism must be tackled. Len claims it doesn't exist, undermining the leader and party efforts to tackle the problem."

Earlier, dozens of Labour MPs marched in support of their colleague Ruth Smeeth before she gave evidence against a suspended party member at a disciplinary hearing, where he is accused of anti-Semitism.

They were met by a small number of protesters carrying banners and chanting "reinstate Marc Wadsworth".

Mr Wadsworth, who has been suspended from the party following a complaint of anti-Semitism, said he was confident he would be "exonerated" at a hearing in central London.

Thanking his supporters, he said: "I have been waiting for two years for this. It's been torture. It's been agony. I have been hung out to dry."

At Westminster, a Labour spokesman stressed how Mr Corbyn had made absolutely clear that "he will lead the drive to eradicate anti-Semitism from the party and will not tolerate it".

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He described Tuesday's meeting with Jewish groups as "constructive" and said the Labour leader "regards it as completely understandable that leaders of the Jewish community want to see action and not just words".

But Jonathan Arkush, President of the Board of Deputies of British Jews and Jonathan Goldstein, who chairs the Jewish Leadership Council, said "a deep cultural change" was needed within Labour to rebuild trust.

Elsewhere, Labour HQ made clear the party's ruling National Executive Committee had blocked a parliamentary candidate who had suggested on social media that the Manchester Arena bombing might not have happened.

Mandy Richards was selected as the party's prospective MP for the winnable seat of Worcester despite messages on her Twitter feed raising questions over why there were "no images...of physical damage" from the bombing and said there was a "convenient shortage of evidence" in the murder of the late MP Jo Cox.