Nick Clegg has been accused of "having no backbone" following his call for an arms embargo on Israel. The Liberal Democrat leader and Business Secretary Vince Cable, pushed for a full suspension of licences for arms exports.
Mr Clegg said the Israeli military had "overstepped the mark in Gaza" and Britain should act in response.
But political opponents said it was hypocritical of him to pursue a hard line on Israel because of his record of dealing with his colleagues' own controversial statements.
The Lib Dems have yet to take disciplinary action against MP David Ward after he said last month he would "probably" be willing to fire a rocket at Israel if he lived in Gaza.
As we went to press, a government spokesman said a review of existing arms export licences to Israel was ongoing and no new licences would be issued at the moment. Mr Clegg hopes the temporary suspension can be made permanent.
A government spokesman said: "Suspending export licences is not a decision we take lightly and it is right that we examine the facts fully."
The Jewish Leadership Council said it was "deeply concerned" by Mr Clegg's comments.
"He notes the vast sums of aid money spent by Hamas on constructing a sophisticated network of terrorist tunnels under Israel but is unable to accept that Israel has the responsibility to confront and decommission these threats.
"It is hard to imagine that, if missiles were landing on London and Manchester, or terrorists were emerging from attack tunnels in Birmingham and Leeds, the Deputy Prime Minister would assert that Britain should demonstrate 'magnanimity' and use 'political will, not military might'."
The LibDem Friends of Israel said: "Arms export licences are almost always under review. At times of conflict, governments naturally wish to take stock...Nick Clegg is a friend of Israel both politically and personally. Some legitimate questions have been asked and rightly so. LDFI has worked with the party leadership and within the wider party to continually strive for balance in comments made. "
Mr Clegg said the resignation of Baroness Warsi from the government, and her highlighting of Britain's sale of arms to Israel, had raised "very serious questions. I share her concerns".
He said: "The Israeli military operation overstepped the mark in Gaza. That's why I believe that the export licences should now be suspended."
A Lib Dem spokesman said Mr Clegg had previously condemned Mr Ward's comments and that disciplinary action against the Bradford West MP was ongoing.
International Development Secretary Justine Greening said Britain would send an additional £2 million to UNWRA's Gaza emergency appeal. The money will be used for mattresses, blankets and equipment for 8,000 Palestinian families and brings the UK's contribution in the past two weeks to £15m.