Battle lines drawn: PMQs reveals referendum dividers for 2015 election

David Cameron's impending promise of a referendum on Europe is pitting Conservative claims of advancing Britain's "national interest" against Labour's warnings on the economy, today's prime minister's questions revealed.

Fierce exchanges across the despatch boxes between Cameron and Ed Miliband seemed to preview the battle lines the parties will take at the 2015 general election.

After a hard-fought set of questions and answers the prime minister finished by offering a stark choice on Europe – one likely to be hotly disputed by Labour.

"If you want to stay out of the single currency, you vote Conservative. If you want to join the single currency, you vote Labour," he declared.

"If you want to take power back to Britain you vote Conservative, if you want to give power back to Brussels, you vote Labour."

That followed a session in which Conservative arguments for a renegotiation in Britain's "national interest" clashed with Labour warnings about the uncertainty for businesses such an impending referendum will bring.

"There is a massive change taking place in Europe, a change being driven by the changes in the eurozone," Cameron said, after Miliband pointed out he had failed to end the days of the Tory party "banging on about Europe".

"This country faces a choice," the PM continued,

"Do we look at these changes and see what we can do to maximise Britain's national interest, or do we sit back and tell the public to go hang? I know where I stand, and that's in the national interest."

Miliband reminded Cameron they had walked through the voting lobby together against an in-or-out referendum in the October 2011 division which saw 81 Tory MPs vote against the prime minister.

"I don't think it would be right for Britain to have an in-out referendum today because we'd be giving the British people a false choice," Cameron replied.

"Throughout Europe, countries are looking at forthcoming treaty change and thinking what can I do to maximise my national interest? That is what the Germans will do. That is what the Spanish will do. That is what the British should do."

Miliband suggested the prospect of a potential UK exit from the European Union would have a negative effect on the UK economy.

"An in-out referendum now would be destabilising, but promising one in five years' time is just fine for the country," he said, sarcastically summing up the PM's views.

"That is five years of businesses seeing a closed for business sign hanging around Britain."

He quoted former Tory Cabinet minister Michael Heseltine warning that committing to a referendum was taking an "unnecessary gamble". Cameron responded by pointing out Heseltine had originally supported calls for Britain to join the single currency.

"What business wants in Europe is what I want in Europe: for us to be part of Europe, but a more flexible, competitive Europe," the prime minister said.

"When there is change taking place in Europe, when the single currency is driving change, isn't it in Britain's national interest to make the European Union more competitive and flexible?"

Miliband replied: "It's nothing to do with national interest – he's lost control of his party. He thinks his problems on Europe will end on Friday. They are just beginning."

That prompted Cameron to mount an offensive of his own against Labour's record on Europe, in which he suggested the current situation was largely the last government's fault.

The PM asked: "Doesn't he understand that what has happened over the last decade, where a Labour government signed treaty after treaty, gave away power after power, and never consulted the British people, is what has made this such a big problem in the first place?"

Miliband rejected that argument, concluding by claiming: "When it comes to Europe, it's the same old Tories – a divided party and a weak prime minister."