(JTA) — Former London Mayor Ken Livingstone reiterated his claims that Hitler supported Zionism, claims that got him suspended from Britain’s beleaguered Labour Party.

Livingstone on Monday returned to the BBC London morning radio show where he made the original remarks five months ago, in defense of Labour lawmaker Naz Shah, who was suspended a day earlier over a Facebook post in 2014 suggesting Israelis should be moved en masse to the United States. This time he used Israel’s Yad Vashem Holocaust museum to bolster his claims.

“The fact 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,” Livingstone told BBC interviewer Vanessa Feltz.

“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 also said.

“If you go to the Holocaust Memorial at Yad Vashem in Israel, one of the pamphlets they sell to tourists there is one that talks about the deal that was done between Hitler and the Zionists in the 1930s. If you are being given that at the Holocaust Memorial I think you might suspect it is true,” he concluded.

After he made the original comments in April, Livingstone was suspended from the Labour Party, amid accusations that the party and its leader, Jeremy Corbyn, had not done enough to curb rampant anti-Semitism among party members.

A government inquiry into anti-Semitism was launched in April to determine whether anti-Jewish prejudice has increased in the U.K. and to assess the particular dangers facing Jews.

During an interview as part of the inquiry, Livingstone said he regretted his remarks because of the “hysterical response” to them.

“I am horrified by the way my remarks have been interpreted and twisted. I cannot think of a worse insult than to be called a racist or an anti-Semite. And I am sorry if what I said has caused Jewish people, or anyone else, offense. That was not my intention,” he told the government panel.

Livingstone was suspended from the party less than a week after he made the original remarks, and faces expulsion for doubling down on the remarks since then. He told Feltz on Monday that it is 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.”

The Board of Deputies of British Jews called on Labour to expel Livingstone from the party, the London-based Jewish Chronicle reported.

Marie van der Zyl, vice president of the Board of Deputies, accused Livingstone of attempting to “rewrite history to make it seem like Zionism was responsible for the Holocaust, which is as false as it is grotesquely offensive.”

“Every day that Labour does not expel him is a stain on the party,” she said according to the Chronicle.