Holocaust revisionism is to blame for Countdown's Rachel Riley "getting crap" after she challenged anti-Semitism, the Commons has heard.

Labour MP John Mann (Bassetlaw) warned such revisionism is the "plague we have to challenge and fight" rather than the "ignorant and thick Holocaust deniers of the past".

Mr Mann said attempts to revise attitudes towards the Holocaust are "not just a British problem" but exist all over Europe, and it is also a "problem" in the Labour Party.

Speaking during a Commons debate on Holocaust Memorial Day, Mr Mann said of Holocaust revisionism: "Those who want to twist and turn what happened for their own ends, who'd like to give some lip service but only some in twisting the facts, in minimising the consequences and the implications.

"We have seen it in the last few days with the TV personality Rachel Riley and the abuse she has received from many for standing up to anti-Semitism.

"Well, I stand and I hope we all stand with Rachel Riley in her bravery as a young woman, one amongst many, one of the better known, therefore the more abused for standing up against modern anti-Semitism.

"It's a problem all over Europe, it's a problem in my political party, it's problem in this country, it's a problem we're not facing up to sufficiently robustly or successfully.

"That's why Rachel Riley's getting all the crap she's getting at the moment.

"Holocaust revisionism - of not understanding the realities of what happened and what that means for today.

"That's why I'm angry but I endorse, and I'm sure we all endorse, Holocaust Memorial Day today."

Labour former minister Ian Austin, whose father's family were killed in the Holocaust, gave a moving speech to open the debate.

The MP for Dudley North talked about how his father was put on a train to England, where he grew up to be a headmaster, his grandmother and great-aunt were sent to a ghetto, and eventually to the Treblinka death camp in 1942.

Reflecting on the row around anti-Semitism in Labour, Mr Dudley said: "One of the reasons I joined the Labour Party as a teenager in Dudley 35 years ago was to fight racism and I believe that just as passionately now as I did then.

"And I'm shocked that a party that has such a long tradition of fighting racism has caused such offence and stress to the Jewish community.

"Labour members must understand that we won't have any right to criticise our opponents on these issues if we don't get our own house in order first."

He was praised by the MPs who spoke after him, and the DUP's Jim Shannon walked along the opposition benches to pat him on the back.

Conservative former cabinet minister Stephen Crabb later revealed his "shame" at not calling out an anti-Semitic comment by an ex-Tory MP.

He said: "I remember one incident as a new MP in my first term in the tea room talking to a colleague about a forthcoming CFI (Conservative Friends of Israel) trip to Israel and this rather grand colleague who is no longer in his place said to me 'be careful young man, wouldn't be the first gentile to be taken in'.

"And I'm ashamed to say that I let that remark go. But it's a remark that speaks and reflects directly the dark stereotypes of Jewish people reflecting ideas of conspiracy and manipulation and deception."