- David Cameron will on Wednesday vow to settle Britain's future in the European Union
- Will promise a straight in-out referendum by 2017, a high risk strategy
- Will test the willingness of Paris and Berlin to cut the UK a better membership deal
David Cameron will on Wednesday vow to settle Britain's future in the European Union with a straight in-out referendum by 2017, in a high-risk strategy which will test the willingness of Paris and Berlin to cut the UK a better membership deal.
The prime minister will tell the rest of the EU that Britain could "drift towards the exit" unless he is able to win an improved deal, and will lay down a tight timetable for a renegotiation.
In a long-awaited speech on Europe, Mr Cameron will say: "It is time for the British people to have their say. It is time to settle this European question in British politics."
The promise of a referendum if the Conservatives win the 2015 general election will delight his eurosceptic party; Tory MPs believe the rest of Europe will make concessions to London as part of a deal to keep Britain in the club.
But Mr Cameron's speech is carefully calibrated to reassure British business and the rest of Europe that he wants to negotiate in good faith and that he wants to campaign vigorously to stay in the EU when the moment comes.
He will say: "Over the coming weeks, months and years, I will not rest until this debate is won -- for the future of my country, for the success of the European Union and the prosperity of our peoples for generations to come."
But his referendum strategy has been dubbed "a gamble" by Tory cabinet minister Ken Clarke and it rests on Mr Cameron's assumption -- questioned by many in Brussels -- that the rest of Europe will negotiate a new deal with Britain.
Mr Cameron's aides refuse to say whether the prime minister would campaign for a Yes vote if he was unable to repatriate powers from Brussels -- his shopping list could include areas such as employment law, regional policy and fisheries.
He also wants to protect Britain's European position -- and the integrity of the single market -- as the eurozone becomes an increasingly integrated inner core.
The prime minister's strategy is based on a belief that the EU will negotiate a new treaty some time after the 2015 British election to reinforce political and fiscal union in the eurozone -- throwing open a wider debate about Europe's future.
He argues that Britain could veto such a treaty if he did not get his way, a position viewed by allies of Angela Merkel, German chancellor, as "blackmail". Meanwhile France has made it clear that Mr Cameron cannot "cherry-pick" which parts of the EU treaties should apply to Britain.
However if the eurozone countries decided they could bolster the single currency without a new treaty, Mr Cameron would then be faced with trying to carve out a special deal just for the UK.
Mr Cameron will tell an audience in central London that "democratic consent for the EU in Britain is now wafer thin" and that ignoring the question about the country's European future will not make it go away.
"In fact, quite the reverse," he will say. "Those who refuse to contemplate consulting the British people would in my view make more likely our eventual exit."