The Liberal Democrats have distanced themselves from comments made by party peer Jenny Tonge during an Israel Apartheid Week event.
Speaking to an audience at Middlesex University's Free Palestine Society she said Israel would "not last forever".
"Israel will lose support and then they will reap what they have sown," she added.
Baroness Tonge said Americans would tell "the Israel lobby in the USA: enough is enough".
A Lib Dem spokesman said Baroness Tonge's comments at the event last Thursday were not reflective of party policy and that her presence at the event was "extremely ill-advised and ill-judged".
Labour leader Ed Miliband responded to the comments by tweeting: "No place in politics for those who question existence of the state of Israel. Nick Clegg must condemn Jenny Tonge's remark and demand apology."
Mr Clegg originally sacked Baroness Tonge from her role as Lib Dem health spokesperson in the Lords in 2010 after she called for an inquiry into allegations Israeli Army staff trafficked organs while helping Haiti earthquake victims.
She was previously sacked in 2004 by Charles Kennedy for suggesting she would consider becoming a suicide bomber.
Baroness Tonge had preceded her comments on Israel by "welcoming" the JC to the event at the university's Hendon campus.
She said: "Can I give a big welcome to the Jewish Chronicle, I am sure they are here. Thank you for coming. I hope we give you lots of things you can say about us.
"However any of you like to interpret my remarks, I am not antisemitic. It is injustice that concerns me most.
"I am certainly anti the current Israel government and I am anti the Israel lobby that supports that government.
"I am not antisemitic. Get it? It is very important to make that distinction."
Baroness Tonge said that when the Israel lobby "decide to go for you, they will go for you in a big way. I bear the scars."
Labour Friends of Israel chairman John Woodcock MP said: "Nick Clegg must act. Comments and remarks such as these have absolutely no place in mainstream politics. Words of excuse or apology in response are no longer enough.
"Nick Clegg needs to take disciplinary action against his offensive peer to reassure people the government remains serious about a two-state solution."
Finchley and Golders Green MP Mike Freer said: "This is not a case of Baroness Tonge misspeaking but the most recent of a series of vehemently anti-Israeli statements and sharing platforms with people that I would consider extremists. Nick Clegg must bite the bullet and remove the Liberal Democrat whip from her once and for all."
A Liberal Democrat spokesman said: "Jenny Tonge does not speak for the party on Israel/Palestine. Her presence and comments at this event were extremely ill-advised and ill judged. The tone of the debate at this event was wholly unacceptable and adds nothing to the peace process.
"The Liberal Democrats are wholehearted supporters of a peaceful two-state solution to the Israel/Palestine issue."
The Board of Deputies of British Jews and the Jewish Leadership Council also called for the whip to be removed "immediately".
"Given her long-standing, pernicious views on Israel, her comment that Israel 'is not going to be there forever' is both sinister and abhorrent," they said. "There is no place for someone like Jenny Tonge in mainstream political parties in this country and it is time for the Liberal Democrats to act quickly and decisively, once and for all."