Prime Minister David Cameron on Tuesday promised to let dissenting ministers campaign for Britain to leave the European Union once he has reached agreement with the bloc's leaders on his demands for reform.
Cameron has promised to renegotiate the terms of Britain's EU membership before holding an in-out referendum by the end of 2017.
"My intention is that at the conclusion of the renegotiation, thegovernment should reach a clear recommendation and then the referendum will be held," he told parliament.
"But it is in the nature of a referendum that it is the people, not the politicians, who decide," Cameron said.
"As I indicated before Christmas, there will be a clear government position, but it will be open to individual ministers to take a different personal position while remaining part of the government."
Cameron's announcement paves the way for eurosceptic ministers to press for a "Brexit" - a British exit from the EU - in campaigning ahead of the referendum.
He said "difficulties were raised" in negotiations with EU leaders on all four areas where Britain is seeking reform: competitiveness, sovereignty, social security and economic governance.
But Cameron said he believed "there is a pathway to agreement" on Britain's demands.
Cameron will travel to Germany on Wednesday for a conference of Germany's Christian Social Union party, an ally of Chancellor Angela Merkel's Christian Democrats, sources told dpa.
He is expected to win support from the CSU for his demand to limit access to welfare benefits for EU migrants, a move that critics say would contravene the EU's principle of allowing freedom of movement.
Voters in the referendum are expected to be asked the single question: Should the United Kingdom remain a member of the European Union or leave the European Union?
Many analysts expect the vote to take place this year.
No ministers have publicly backed a "no" vote in the referendum, but British media have speculated that at least two cabinet ministers support Brexit and others could join them if they are dissatisfied with Cameron's deal.