Labour's candidate in the Rochdale by-election has apologised for remarks he made about Israel in a local party meeting.
In a secret recording obtained by the Mail on Sunday, Azhar Ali reportedly said Israel had "allowed" the deadly attack by Hamas gunmen on 7 October.
Mr Ali said his claims had been "deeply offensive, ignorant, and false".
The Tories have called for Labour to suspend its by-election campaign and remove Mr Ali's party membership.
Labour's national campaign co-ordinator Pat McFadden told the BBC Mr Ali's comments "were completely wrong" and did not represent the party's view.
Mr Ali will remain Labour's candidate in the Rochdale by-election, Mr McFadden also told Sky News.
In the recording, which has not been heard by the BBC, Mr Ali is alleged to have said: "The Egyptians are saying that they warned Israel 10 days earlier... Americans warned them a day before [that] there's something happening... They deliberately took the security off, they allowed... that massacre that gives them the green light to do whatever they bloody want."
Gunmen from the Palestinian group Hamas broke through the border at Gaza and infiltrated southern Israel on 7 October, killing more than 1,200 people - mainly civilians - and taking around 250 others hostage.
Since then, the territory's Hamas-run health ministry says Israeli attacks have killed more than 28,100 people in Gaza - most of them women and children.
Israeli authorities have faced criticism for security failings and reports have emerged that intelligence services were warned by Egypt of potential violence in the days leading up to the attack. Prime minister Benjamin Netanyahu has described the reports as "absolutely false".
In a statement, Mr Ali said: "I apologise unreservedly to the Jewish community for my comments which were deeply offensive, ignorant, and false.
"Hamas' horrific terror attack was the responsibility of Hamas alone, and they are still holding hostages who must be released."
Appearing on the BBC's Sunday with Laura Kuenssberg earlier, Labour's Mr McFadden said he was "appalled" by the comments.
"He has quite rightly apologised and completely retracted and I hope he learns a lesson from it," he said.
"Those comments were completely wrong and they certainly don't represent the Labour party's view."
Conservative Party chairman Richard Holden called for Labour leader Sir Keir Starmer to "immediately remove Mr Ali's Labour membership and suspend Labour's campaign" ahead of the by-election on 29 February.
He said: "Time after time, Sir Keir Starmer says that he's changed Labour. Time after time we're seeing that simply isn't true."
In his apology, Mr Ali said 7 October had been "the greatest loss of Jewish life in a single day since the Holocaust, and Jews in the UK and across the world are living in fear of rising antisemitism".
The Lancashire county councillor said he wished to "urgently apologise to Jewish leaders for my inexcusable comments".
The Board of Deputies of British Jews said it would have called on Labour to replace Mr Ali as a by-election candidate had it not been too late to do so.
Describing his earlier comments as "disgraceful and unforgivable", the board said: "It is clear to us that Mr Ali is not apologising out of a genuine sense of remorse.
"Despite what he says in his apology, we do not see how we could possibly engage with him at this time, and we believe other leading Jewish communal groups will feel similarly."
In the recording, Mr Ali also reportedly disagreed with a comment at the meeting about Sir Keir being "held in high regard".
According to the Mail, he said: "A lot of the MPs I've spoken to - non-Muslim MPs - feel that on this issue, he's lost the confidence of the parliamentary party."
A number of Labour frontbench MPs and councillors have resigned over the party's initial reluctance to call for a ceasefire. There was also controversy after Sir Keir appeared to claim in October that Israel had a right to cut off power and water from Gaza, although he later said he was instead supporting Israel's right to self-defence.
In his latest statement, Mr Ali said: "The Labour Party has changed unrecognisably under Keir Starmer's leadership, he has my full support in delivering the change Britain needs."
The by-election follows the recent death of previous incumbent Sir Tony Lloyd.
The Green Party candidate Guy Otten recently confirmed he was withdrawing from the contest after "some regrettable social media posts I made a number of years ago".
However, his name will still appear on the ballot paper, as the decision followed the deadline for nominations.