* Rifts over Europe widen in ruling Conservative Party
* EU rebels to vote against Cameron in parliament
* Senior ministers say they would vote to leave EU
British Prime Minister David Cameron moved to end a damaging revolt over European Union membership in his ruling Conservative party on Monday, saying his ministers all backed him on the issue even though two had expressed more sceptical views than his own.
Cameron's promise to renegotiate Britain's relationship with the EU and hold a plebiscite on membership if he wins the next election in 2015 has failed to end his party's divisions over Europe or halt the rise of the anti-EU UK Independence Party (UKIP).
Cameron is keen to unite his party on Europe, an issue that helped bring down Conservative prime minister Margaret Thatcher and dogged her successor John Major, another Conservative.
Two cabinet ministers suggested on Sunday they would vote to leave the EU if a referendum were held today, while Cameron has always said he wants Britain to stay in a reformed EU.
A powerful wing of his own party worried about losing votes to UKIP is pushing him to enshrine his promise of a referendum in law now. However, Cameron cannot do so because his pro-EU junior coalition partners, the Liberal Democrats, oppose such a move.
Despite a growing clamour in his party to harden his line on Europe, Cameron stuck to his pledge to try to reform Britain's EU role, saying it was "very, very strange" to give up before renegotiation talks have begun.
"I don't think that the status quo in the EU is acceptable today," Cameron told reporters in Washington, where he was meeting President Barack Obama to support the case for a U.S.-EU trade deal.
"I want to change it and, having changed it, I then want to ask the British people a very simple in/out question."
Cameron said all his ministers were "confident we'll be able to deliver those changes".
Eurosceptics in the Conservative Party see the European Union as an oppressive, interfering and wasteful "superstate" that threatens Britain's sovereignty and puts an excessive regulatory burden on its companies.
The prospect of a British withdrawal from Europe after 40 years has rattled many business leaders, however. They fear that pulling away from Britain's biggest trading partner will badly damage its fragile economy.
To compound Cameron's discomfort, up to 100 eurosceptic Conservative members of parliament are expected to back an amendment this week criticising legislative plans unveiled by the government because they did not include a bill paving the way for a referendum on Britain's EU membership.
London Mayor Boris Johnson, a member of Cameron's Conservatives and a potential leadership rival, said he supported the idea of passing a law now to guarantee an EU referendum will take place.
However, Cameron played down the prospect of such a move.
"Coalition does throw up different circumstances," Cameron added, saying headlines about the vote were "over-excited", a reference to some stories claiming his party was embroiled in a civil war.
UKIP leader Nigel Farage, whose party made big gains in local elections this month, said the only way Cameron could solve his Europe problem was to hold a referendum before the next election.
"If he doesn't, then I think he will go on leading a party that is hopelessly split," Farage told the BBC. "I think the dam has broken. I think the politics that dare not speak its name has now become mainstream."
Officials in several European countries warned Cameron he could not have an "a la carte Europe", choosing the bits he liked while discarding other parts he didn't. Several high-profile internal critics have also said Cameron has no chance of reworking Britain's EU membership.
Cameron strongly rejected that idea.
"You shouldn't give up before a negotiation has started," Cameron said. "The idea of throwing in the towel before the negotiations have started is a very, very strange opinion."