Jenny Tonge has had her party membership suspended by the Liberal Democrats.
The peer's suspension follows a series of incidents for which she was sharply criticised by the Jewish community.
A Lib Dem spokesperson confirmed the suspension this afternoon, saying: “The party has suspended the membership of Jenny Tonge. We take her comments very seriously and have acted accordingly.”
It was later reported that Baroness Tonge had resigned her membership of the party.
Writing on Facebook, she said: "In the course of the evening one member of the audience made a 'rant' against Israel quoting some very confused history which I confess I did not hear or understand! I then called the next member of the audience and moved on. The contribution was ignored by the audience after a few claps of relief! Apparently this is my sin!
"I am at last free of being told what I must and must not say on the issue of Palestine, lest it offends the Israel lobby here, who like to control us, as they do in the USA.
"They are trying to destroy the Labour Party with spurious accusations of antisemitism and now they have set their sights on the Lib Dems.
"I have never been antisemitic, and never will be. I am anti-injustice and that is why I criticise the Israeli government's flagrant disregard for international law and human rights in the Occupied territories of Palestine and Gaza."
The peer stepped down from the party's parliamentary group in 2012 after being given an ultimatum by then-leader Nick Clegg to leave or apologise for previous anti-Israel comments.
She has not taken the party's whip in Lords since.
On Tuesday evening Baroness Tonge hosted an event in the House of Lords which was organised by the Palestine Return Centre. One of the commenters at the meeting appeared to blame the Jews for the Holocaust.
Attendees applauded when another member of the audience claimed that “if anybody is antisemitic, it’s the Israelis themselves.”
Last week Baroness Tonge published a letter online which she said she had sent to The Guardian. In the letter, she discussed the Home Affairs Committee’s report on antisemitism, saying: “It is difficult to believe that a 75% increase in antisemitism it reports, have [sic] been committed by people who simply hate Jewish people for no reason.”
Lord Polak, Conservative Friends of Israel honorary president, called the suspension "long overdue", referring to Baroness Tonge's "shameful record of twisted, anti-Israel rhetoric."
Speaking to the JC, Lord Carlisle, the Liberal Democrat Peer, said:
“I have some experience of representing persons subject to investigation by the party. I have done this on two occasions. The procedure can be cumbersome; however, on this occasion I expect the party to appoint as investigator somebody who is not a party member and is completely independent without any interest of their own to serve.
“There should also be a short and realistic time limit for the completion of this inquiry.
“I would add that this could be short-circuited by Baroness Tonge’s resignation from the party, which would be welcome and permanent.”
Gavin Stollar of Lib Dem Friends of Israel said: "Finally Baroness Tonge has reaped what she has sown. She is neither a defender or promoter of the Palestinian cause, rather an anti-Israel zealot who can now espouse her offensive views outside our party."
Jennifer Gerber, Director of Labour Friends of Israel, referenced the lack of "reproach or redress from Baroness Tonge as chair" at the Palestine Return Council event, where, she said, "attendees compared Israel to ISIS and claimed Jews ‘provoked’ their own genocide."
"Silence in the face of such abhorrence amounts to tacit endorsement", she said.
"We welcome the swift suspension of Baroness Tonge by the Liberal Democrats."
Jonathan Arkush, president of the Board of Deputies of British Jews, said: “Jenny Tonge’s suspension from the Liberal Democrat Party has to be the right decision.
"Yesterday, we raised her antics as a key topic in our meeting with Liberal Democrat Leader Tim Farron and it is heartening that our comments were taken on board.”
Simon Johnson, chief executive of the Jewish Leadership Council also welcomed the move.
He said:"It is high time that Baroness Tonge was suspended from the Liberal Democrats and I welcome this step by the party. It is long overdue. Baroness Tonge’s anti-Israel hatred is there for all to see and I trust that the Liberal Democrats will now conduct a proper disciplinary process and continue to take steps to counter anti-Israel hatred within their party.”