14 January 2013 Last updated at 05:52 ET

Article written by Nick Robinson Political editor

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David Cameron says there will be EU referendum if...

 

You hear David Cameron saying on Today people feel increasingly left out of the debate, you hear him say he wants the country to give its full-hearted consent. Ha! You say, yes he's going to give us a referendum on Europe at last.

But just be a little careful - the prime minister has ruled out an in/out referendum now on Europe. In other words a choice now about whether we stay or go - he's ruled it out before the next election.

In other words, what we learned from the Today programme interview, which is a dramatic shift - we'd had hints and nudges before - is that he has set out how we might get that referendum on Europe after the next election, but there is a series of ifs:

• If he wins the next election alone (in other words doesn't have to get this past Nick Clegg)
• If he can persuade other European countries, particularly Germany that they need and want treaty change
• If Britain can then get what it wants in negotiations
• If he thinks he can then win a referendum

If all that happens, well then, yes, there will be a referendum which he thinks will approve a new better settlement for Europe.

But his difficulty in giving that big speech on Europe in about a week's time is what if he's wrong on any one of those ifs?

Because then the pressure will remain on him from within his party and from outside, not least the UK Independence Party, saying they are not willing to wait for those ifs, saying they are not willing to wait all that time, saying that they are not willing, in other words, to trust him.

Saying, in short, "we want our choice now".

But essentially, what has happened today is that the prime minister has shifted to say you WILL get a referendum one day - in certain circumstances.