Signs of growing diaspora discontent with Israeli policy have emerged with the launch of a petition by American Jewish figures calling for a settlement freeze and a compromise over Jerusalem's sovereignty.
For the Sake of Zion was inspired by a European initiative, JCall, headed by French Peace Now earlier this month.
The campaign has exposed sharp divisions in Britain in attitudes to Israel. Paul Usiskin, chairman of British Peace Now, said there was "increasing anxiety" over the direction of the Israeli government. "Voices of criticism in Europe have been dismissed by Israel for too long. But those voices in America will resonate with the diaspora."
But Samuel Hayek, chairman of JNF UK, said: "The Israelis are not stupid natives waiting for their brothers and sisters across the ocean to tell them how to compromise their security."
The US petition, which has collected 800 signatures, says: "As our European counterparts correctly point out, 'the occupation and the continuing pursuit of settlements in the West Bank and in the Arab districts of Jerusalem … are morally and politically wrong and feed the de-legitimisation process that Israel currently faces abroad.'"
It was the right of American Jews to "call attention to decisions the government of Israel takes which, in our view, endanger the state we hold so dear".
The petition's organising committee includes such figures as the leading Jewish sociologist Professor Steven Cohen; political theorist Professor Michael Walzer; Rabbi Irwin Kula, president of the educational organisation Clal; and musician Theodore Bikel.
It has come as a response to public attacks on President Obama's approach to Israel, from, among others, the World Jewish Congress head, Ronald Lauder.
Colin Shindler, professor of Israeli studies at London's School of African and Oriental Studies, said the petition "reflects the growing unease of loyalist US Jews with the political stagnation in Israel and the policies of the Netanyahu government regarding settlements".
He added that it probably also reflects "the views of a majority of British Jews. Many Jewish leaders here would privately agree that such policies undermine their efforts against delegitimisation, disinvestment and the boycott."
Lucian Hudson, chairman of Liberal Judaism, said: "I believe we have to adopt a policy of constructive critical engagement with Israel, highlighting its achievements but equally taking issue with aspects of its policy.
"We've yet to cross this Rubicon in the UK, but we need to get there. People fear that if you criticise Israel openly, you give succour to its enemies."
But Andrew Balcombe, the Israel-based chair of the UK's Zionist Federation, said: "The real debate is here. Those who want to make a genuine difference, and not just sound off for effect, should come and influence events, as I did. It is much more effective than signing petitions."