David Cameron has sought to reassure eurosceptics he is prepared to hold a referendum on Britain's relationship with Brussels - but only when there is a "real choice" for voters.
The Prime Minister insisted that an immediate in/out referendum - which he is under mounting pressure from within his own party to deliver - was not what the vast majority of people wanted.
But, in an article for The Sunday Telegraph, he acknowledged the need to ensure the UK's position within an evolving European Union has "the full-hearted support of the British people".
"There is more to come - further moves, probably further treaties - where we can take forward our interests, safeguard the single market and stay out of a federal Europe," he said.
"How do we take the British people with us on this difficult and complicated journey? How do we avoid the wrong paths of either meekly accepting the status quo or giving up altogether and preparing to leave? It will undoubtedly be hard going, but taking the right path in politics often is.
"As we get closer to the end point we will need to consider how best to get the full-hearted support of the British people, whether it is in a general election or a referendum. As I have said, for me the two words 'Europe' and 'referendum' can go together, particularly if we really are proposing a change in how our country is governed, but let us get the people a real choice first."
Mr Cameron said he agrees with the "vast majority of the British people" who he said were not happy with the UK's relationship with the EU. There were large amounts of EU legislation that should be scrapped, he said.
"Put simply, for those of us outside the eurozone, far from being too little Europe, there is too much of it. Too much cost, too much bureaucracy, too much meddling in issues that belong to nation states or civil society or, indeed, individuals," he said. Whole swathes of legislation covering social issues, working time and home affairs should, in my view, be scrapped."
Foreign Secretary William Hague said there would be a "very, very powerful" case for a referendum if Europe moved towards a more federal system, as expected in response to the eurozone crisis.
But he said the Government wanted to see whether it could negotiate a better relationship between the UK and Brussels, with the return of powers, before putting the matter to the British people.