But Cameron is playing a dangerous political game with delayed referendum, writes Richard Porritt

Because “in or out” is going to be the question on everyone’s lips until 2018 when Britain will once again decide whether it is worth our while being in the EU club – if the Tories win the next general election, of course.

This is a spectacular move by the Prime Minister in two respects: It is brave and it has all but sealed the 2015 election in his favour.

After Britain became l’enfant terrible when the EU leaders last met and Mr Cameron dug his heels in, this column called the 2015 election in his favour. Now all but the tiniest doubt has gone.

At Prime Minister’s Questions yesterday Labour leader Ed Miliband tried in vain to re-open the gulf between the PM and the rest of his party by pointing out they would probably vote in different directions, but it does not matter.

All modern Conservative leaders have been battered and bruised over the Euro question – the party grass roots think Britain should go it alone yet the top brass prefer the security blanket of being there when the decisions of our biggest trading partner are made.

Mr Cameron has been clear – he wants Britain to remain a part of Europe.

Now the clamour, not only from the backbenches but from the shires, has become too much – the threat from UKIP is deafening.

And, talking to East meets Westminster after Mr Cameron made his watershed speech, UKIP leader Nigel Farage said although he was delighted the issue was on the agenda he was not holding his breath that Britain would ever actually make it to the polls.

“Let’s not pretend the Prime Minister ever wanted to make this speech,” he said. “He was forced into it because of UKIP – if this party did not exist the Government would not be making these proposals.

“So, I am pleased that an issue we were told we must not discuss in front of the children is finally out in the open again.

“But why do we have to wait another five years? By then the floodgates will once again have been opened to countless unskilled labour arriving on these shores and we will have spent £70billion we did not need to.

“This was a cynical speech made by a career politician desperately trying to cling to power.”

And his fury was not just aimed at the PM: “Another astonishing aspect is the Labour party’s stance – they clearly do not trust the people of Britain because they do not want them to have their say.”

Whatever people think of Mr Farage his stance has struck a chord with a lot of voters. And he is right to doubt Mr Cameron because his record on Europe is rather chequered.

During yesterday’s speech he said: “I am in favour of a referendum. I believe in confronting this issue – shaping it, leading the debate. Not simply hoping a difficult situation will go away.”

And yet hoping this difficult situation will go away is exactly what he has done since he took power.

But now – when forced to face up to the fact this boil needed lancing – he is hoping to capitalise.

What if the negotiations with the EU deliver less than he wants? Will he then switch and campaign for the country to leave? Would a successful set of talks prompt him to change altogether and suddenly declare Britain does not need a vote after all – he has form on this front.

The speech leaves the Prime Minister wriggle room – and yet it is a vote- winner.

What yesterday’s speech also does is to shift the focus: Mr Cameron is quite happy for people not to be going to the polls and voting on economic issues alone.

Now the electorate have another topic to be lobbied on. And Mr Miliband can surely already hear the Tory rhetorical ringing in his ears: “Why shouldn’t the people have their say?”

His answer is fair: “This is not the time to be tinkering with EU deals, it is the time to be getting on top of the economy and getting Britain back on track.”

In fact that is almost exactly what the official Tory party line had been until it became clear the economic recovery was going to be slower than hoped and UKIP began to loom large in everyone’s rear-view mirror.

If nothing else Mr Cameron has thrown down a gauntlet the Liberal Democrats and Labour surely can not ignore.

Mr Miliband stands to lose votes over Europe – there are plenty of dyed-in-the-wool reds who are suspicious of our European neighbours.

But for now Mr Cameron will be pleased. He has taken the wind from Mr Farage’s seemingly billowing sails, given Mr Miliband a headache set to last until May 2015 and handed power back to the public – apparently.

But five years is a long time away and how will business react to not being able to confidently know what trading conditions will exist post-2018?

Yesterday’s speech will see Mr Cameron over the line in 2015. But he is playing a dangerous political hand which could yet prove as toxic longer term.