Ken Livingstone says he stands by his earlier statements that Hitler had supported Zionism.

Ken Livingstone, the former London mayor who in April told a BBC Radio interviewer that Hitler had supported Zionism, on Monday stressed that he stands by his statements, Haaretz reported.

Speaking with BBC Radio London's Vanessa Feltz, Livingstone insisted that he has substantial evidence for his earlier remarks, which resulted in his suspension from the British Labour Party.

"After I did the interview with you and I got suspended, I couldn’t walk down the street for people stopping me and saying ‘we know what you said is true – don’t give in to them,'" he told Feltz.

"It’s going to be very difficult for them to expel me from the Labour Party when I’ve got this whole sheaf of documents and papers which shows that what I said was true," Livingstone claimed, according to Haaretz.

"The fact [is] that during the 1930s, Hitler collaborated with the Zionists and supported them because he believed that a solution to his problem – the Jews – was that they should all move to Palestine. Then in the 1940s that changed and he decided on genocide. And that’s the point I made on your program. I’m just surprised that people didn’t check that it was true before they started screaming ‘Nazi apologist,'" he continued.

Livingstone has repeatedly refused to apologize for the comments, even after being harangued as a "racist, Hitler-apologist" by an MP from his own party.

During a recent hearing on anti-Semitism in the British parliament, Livingstone robustly defended his comments, claiming he had been deliberately misrepresented by people who wanted to discredit Labour party leader Jeremy Corbyn.

“If I had said Hitler was a Zionist, I would apologize for that because it’s rubbish,” he said at the time, adding, “If I’d said it, I would agree it was abhorrent. But I didn’t say it. I was stating a simple historical fact.”

In May, the former London mayor was fired from his radio show on LBC Radio, London's most popular talk radio station, over the anti-Semitic comments.

Haaretz noted that this was not Livingstone's first brush with controversy related to the Holocaust. In 2005, he generated anger after asking Jewish reporter Oliver Finegold of the London Evening Standard if he was a "German war criminal" and telling him, "You are just like a concentration camp guard. You are just doing it because you are paid to, aren't you?"