A report in the Daily Mail claimed that Azhar Ali blamed "people in the media from certain Jewish quarters" for fuelling criticism of a pro-Palestinian Labour MP, as well as claiming that Israel planned to "get rid of [Palestinians] from Gaza" and "grab" some of the land.

It is understood that Mr Ali has now been suspended from the party pending an investigation.

Politics live: Why Labour candidate's name will still show on the ballot in Rochdale

A Labour Party spokesperson said: "Following new information about further comments made by Azhar Ali coming to light today, the Labour Party has withdrawn its support for Azhar Ali as our candidate in the Rochdale by-election.

"Keir Starmer has changed Labour so that it is unrecognisible from the party of 2019.

"We understand that these are highly unusual circumstances but it is vital that any candidate put forward by Labour fully represents its aims and values.

"Given that nominations have now closed Azhar Ali cannot be replaced as the candidate."

Mr Ali's candidacy for the by-election later this month had been thrown in the spotlight after the Mail On Sunday reported he had told a meeting of the Lancashire Labour Party that Israel deliberately allowed the Hamas atrocity to take place in order to give it the "green light" to invade Gaza.

Mr Ali had earlier issued an "unreserved" apology for the "deeply offensive, ignorant and false" comments, but Sir Keir had been under pressure to act due to promises he had made to rid his party of antisemitism.

Then later on Monday evening, the further comments came to light, and Labour withdrew support from the candidate.

Sky News has approached Mr Ali for comment.

Speaking to reporters after the decision was made, Labour's national campaign co-ordinator, Pat McFadden, said Sir Keir had taken the "tough but necessary" decision to disown Mr Ali.

"When Keir Starmer became leader of the Labour Party, he said he would change the Labour Party and expect that every candidate and MP would operate to the highest standards," he said.

"And although it is a difficult decision, today, he's put those words into action. And unfortunately we've had to take this difficult decision."

Mr McFadden's comments came despite Mr Ali receiving the support of senior shadow ministers as recently as Monday.

Nick Thomas-Symonds, shadow minister without portfolio, told Sky News on Monday morning that although the comments were "totally unacceptable", Mr Ali had apologised "unreservedly" and would continue to be the Labour candidate.

And hours earlier, Mr McFadden defended Mr Ali on Sky News' Sunday Morning With Trevor Phillips, pointing out that he had issued a full apology and retraction.

But asked what had changed in the last 24 hours, Mr McFadden said: "More comments have come to light which meant we had to look at this situation again.

"Once we saw those comments, Keir Starmer took [the] swift decision, took the tough but necessary action to withdraw support for Mr Ali's candidacy."

Mr McFadden also rejected suggestions Labour had let the Jewish community down, saying Sir Keir's decision was testimony to his pledge to "root antisemitism out of the Labour Party".

"Tonight the decision he has taken is evidence that he is sticking by that, no matter what the circumstances," he added.

Labour's decision to pull support for Mr Ali came after Sky News reported that Labour had received an official complaint from the campaign group Labour Against Antisemitism (LAAS), which branded the remarks "antisemitic".

LAAS, a campaign group founded by Labour members to combat antisemitism within the party but which is unaffiliated to it, called for Mr Ali's immediate suspension as a candidate and party member.

Alex Hearn, a director of the campaign group and member of the Labour Party, submitted a formal complaint against Mr Ali in which he wrote: "The accusation that Jews plotted a massacre of innocent people for their own bloodthirsty gain is antisemitic."

Although Labour has now withdrawn its support for Mr Ali, it is too late for his name to be removed from the ballot paper as the party's candidate.

Lord Mann, a former Labour MP who advises the government on tackling antisemitism, said it was a "bold and brave decision" by the party leadership, and the Jewish community would "take great comfort in the fact that Keir Starmer has been prepared to do it".

Speaking to Sky News, he also said Sir Keir would be "fuming" that Mr Ali had made it through the vetting process and "there may be one or two behind the scenes heads that roll over this".

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Prime Minister Rishi Sunak immediately seized on the developments in Rochdale to further his accusation that Sir Keir had "no principles at all".

"Keir Starmer has been running around for the last year trying to tell everybody 'OK, Labour Party's changed'," he told GB News.

"Well, look what just happened in Rochdale, a candidate saying the most vile conspiracy theories, antisemitic, and what happened?

"He's stood by and sent cabinet ministers to support him, until literally five minutes before I walked on tonight, under enormous media pressure, has decided to change his mind on principle. No principles at all.

"So no the Labour Party hasn't changed. It's a con."

Speaking to Sky News on Tuesday, housing minister Lee Rowley also said the incident "shows the Labour Party is in a real mess".

He told Breakfast With Kay Burley: "It is just extraordinary to see some of the things that are coming out now, some of the conspiracy theories.

"It is showing that the Labour Party really hasn't got a grip on this, that it is a party which has not changed [and] a party which will say anything to win government."

The Jewish Labour Movement statement said the party was "right to cease campaigning" for Mr Ali.

"As he cannot be removed from the ballot, we believe it is correct that he will not sit as a Labour MP if elected," it said.

A spokesperson for the Liberal Democrats said: "Comments in the public domain were already unacceptable.

"Hamas's terrorist atrocities on 7th October were an act of unspeakable evil. The Liberal Democrats are calling for an immediate bilateral ceasefire."

See below the full list of candidates and the political parties they represent:

Azhar Ali, (listed as Labour Party, but now removed as its candidate)
Mark Coleman, Independent
Simon Danczuk, Reform UK
Iain Donaldson, Liberal Democrats
Paul Ellison, The Conservative Party Candidate
George Galloway, Workers' Party of Britain
Michael Howarth, Independent
William Howarth, Independent
Guy Otten, Green Party
Ravin Subortna, The Official Monster Raving Loony Party
David Tully, Independent