Pro-European Conservative MPs have urged the Prime Minister to ensure Britain plays a leading role at the heart of the European Union, in the run-up to David Cameron’s long-awaited speech on Europe.

And they urged him to ignore calls for a referendum on quitting the EU entirely.

The open letter to Mr Cameron was signed by a number of West Midland Conservative MPs including Caroline Spelman (Con Meriden), Margot James (Con Stourbridge) and Peter Luff (Con Mid Worcestershire).

They said: “The Eurozone crisis has given added strength to a growing number of voices calling for Britain to either withdraw from the EU or retreat to the fringes.”

But they added: “This view, often perceived as the default position of our Party, not only challenges official Conservative policy but also fails to reflect the views of many, including those names below, who believe that disengagement from Europe is profoundly contrary to Britain’s national interests.”

And they warned the Prime Minister: “We are concerned that an over-emphasis in your speech on renegotiation and a referendum rather than leadership could undermine the Single Market.”

The letter highlights the fact that the Conservative Party still has a pro-European wing, but it also highlights the divisions within the party, with Mr Cameron under pressure from other backbenchers to promise a referendum which could lead to the UK’s eventual withdrawal from the EU.

As the Birmingham Post reported this week, Midlands Tories calling for an in-out referendum include Michael Fabricant (Con Lichfield), a former party whip.

He said: “Whether people are Eurosceptic or Europhile, most people accept that if the single currency is going to survive then the eurozone will have to become federal.

“Inevitably, there will be a two-speed europe, with countries like the United Kingdom not being in the eurozone.

“The Prime Minister has an opportunity to state clearly what changes he would like to see made to those countries in the eurozone to strengthen the euro, and what competencies can be reclaimed by countries like the UK, which are not in the eurozone.”

He added: “It is all change in Europe, so now is the chance for the UK to seize our opportunity and once we have done so, promise an in-out referendum on Europe once the negotiations are complete.”

“All being well, we could end up with the best of both worlds - membership of the single market but without powers being surrended to Brussels.”

And Chris Kelly (Con Dudley South) said: “I want to hear the PM spelling out how the Government will use this unique period in Europe’s history and development to repatriate more powers, negotiate a better deal with the European Union and offer the British people a final say on the proposed new settlement with the EU with an opportunity to either approve or reject both it and membership of the EU.

“As a member of the generation born after the 1975 common market referendum I, like millions of other Britons, have never had a say on our continued membership of what is now the EU.

“I fully expect the Prime Minister to negotiate hard for a preferential arrangement for Britain in the EU and I expect my party leader to be successful in securing that preferential arrangement. I then look forward to a nationwide debate over whether we should accept the new preferential arrangement or seek withdrawal.”

Many Labour MPs are critical of Mr Cameron for allowing speculation to grow that there could be a vote which in some way resulted in Britain leaving the EU.

Jack Dromey (Lab Erdington) argued that this uncertainty would damage the West Midlands economy, in a Commons debate. He said: “In a global marketplace in which we need to export on the one hand and attract inward investment on the other - particularly in the automotive industry - prolonged uncertainty for years to come as to whether our country will remain in the European Union could deeply damage investment decision.”

But not every Labour MP agrees. Writing in The Birmingham Post, Gisela Stuart (Lab Edgbaston) advised Mr Cameron: “Don’t allow yourself be distracted from that work by those who argue that it destabilises the economy. Would anyone say general elections shouldn’t be held because they could be bad for jobs? Bureaucrats and technocrats don’t like democracy.”

Britain did need to take a decision on its relationship with the Europe because the EU was moving towards full fiscal and political union - a process which would happen whether the UK likes it or not - and we had to make a choice about whether to be a part of it, she said.

Ms Stuart said: “The question for the United Kingdom is: do we say ‘yes’ to that single currency supranational block or do we look towards creating new institutions for those European countries who are not part of the euro and don’t intend to be?”