A Lib Dem peer has quit the party following her suspension for chairing a meeting at which Jews were allegedly blamed for the Holocaust.
Former Richmond Park MP Baroness Tonge oversaw the gathering where Israel was also reportedly compared to so-called Islamic State.
Baroness Tonge, who sits as an independent in the Lords but was still a member of the Lib Dems, had her membership suspended on Thursday.
Later that day, the 75-year-old announced she was quitting the party.
The remarks were made at an event in the House of Lords run by the Palestinian Return Centre - and live-streamed on Facebook.
According to The Jewish Chronicle, one man said Zionism was a "perversion of Judaism" and then implied an American rabbi had provoked Hitler into murdering six million Jews.
The event formed part of the Balfour apology campaign, which calls for the government to "officially apologise for its past colonial crimes in Palestine".
The newspaper also reported another speaker said: "If anybody is anti-Semitic, it's the Israelis themselves".
A Lib Dem spokesperson announced Baroness Tonge had had her membership suspended - adding that the party took her comments "very seriously".
Tory MP David Davies raised the matter in the House of Commons, while Cabinet minister David Lidington said he was "genuinely horrified" by the reports.
Baroness Tonge denied she had not heard the the full "rant".
"I was chairing, I did not make any speeches, I introduced the speakers and in the course of that meeting there was a great rant", she said.
"I remember the rant very well but I don't remember hearing very much of it. It was a rant. I didn't know what this person said".