"I say to the British people: this will be your decision. And when that choice comes, you will have an important choice to make about our country's destiny," he added.
In a swipe and Labour and the Lib Dems, Cameron said those who wanted to "ignore" the issue would not make it go away.
"Those who refuse to contemplate consulting the British people would, in my view, make our exit more likely" he said.
However he rejected calls to hold a referendum immediately. "A vote today between the status quo and leaving would be an entirely false choice," he said.
"While the EU is in flux is not the time to make such a momentous decision about the future of our country. It is wrong to ask people to stay or go before we have had a chance to put the relationship right."
The offer of an in or out referendum will be seen as a crucial concession to backbench Tory MPs, many of whom would have been happy with nothing less.
Amid concerns in Tory circles that Cameron faces a uphill battle to remain in office, let alone win an outright majority in 2015, the speech will also be used to campaign against Nigel Farage's Ukip.
Tory MP George Eustice, who used to be Cameron's press secretary, told BBC Newsnight: "If you do want a new settlement with Europe and you do want a referendum, you have to get behind the Conservative Party."
A referendum is not guaranteed as both Labour and the Lib Dems are opposed. It is unclear if Nick Clegg would agree to let Cameron hold a referendum if the prime minister fails to win a majority and has to form a second coalition.
http://www.huffingtonpost.co.uk/2013/01/22/david-cameron-europe-speech_…
Ends.
Local reaction to EU news
I feel concerned that people will feel this is a ploy of some kind, however sincere its intention. The cynics will say less flattering things as to why the PM has structured this in such a convoluted way. People are much more aware of the the way things can be manipulated in politics to suit the moment. Prior to the last election, when David Cameron gave a "cast iron guarantee" to hold an EU referendum "IF" the Lisbon Treaty had "NOT" been ratified by Labour and "IF" he won the election in 2010. The trouble was Labour had ratified the treaty and there was thus no obligation on the PM to hold that referendum - it is an issue that still haunts because people prefer to forget the "if" and "not" part of the statement.
Whatever, let us hope that there is an immediate block on, or suspension of, the more damaging aspects of the EU dictats and its open border policies to offer some protection until such times as the referendum is held. The fact that the EU has yet to have any budget signed off after more than a decade, would be a strong bargaining argument to withhold any more funding until such times as they are.Perhaps it would have been wiser if the PM had given the electorate a say at the same time as (or even before) the next general election, but that was his decision and we should support it.
One thing is certain, the EU federalists will be pumping out the scare propaganda between now and then - as they can't abide democratic elections, it seems to frighten them when the people are given a chance to have their say.
David Slattery-Christy, Blackpool South Conservatives