A Birmingham MP is urging voters to back proposed new laws for a referendum on leaving the European Union.

Andrew Mitchell (Con Sutton Coldfield) is supporting a campaign launched by Conservative chairman Grant Shapps encouraging members of the public to write to their MP and use Twitter or Facebook to demand a ballot.

The House of Commons is set to vote on whether to hold a referendum on July 5. The measure is backed by the Prime Minister but not by his Liberal Democrat colleagues including Nick Clegg, the Deputy Prime Minister.

It means that instead of introducing the Bill as official government business it has fallen to backbencher James Wharton, a 29-year-old MP who joined the Commons for the first time in 2010, to propose the Bill.

Nonetheless, the Conservative Party is officially backing the Bill, and has launched a campaign urging members of the public to do the same.

The party has set up a website, www.LetBritainDecide.com, to make it easy for people to back Wharton’s Bill. And it is urging voters to discuss the measure on Twitter and Facebook, or to download ready-made draft letters to send to their MP or local newspaper.

Mr Mitchell said: “The Prime Minister has set out a road map which is precisely what Britain needs.

“It means renegotiating our relationship with the EU so that it works better for us, and then giving eveyone a chance to vote in a referendum. I strongly support the Bill and will be voting for it, and I support the party’s campaign.”

Conservative Party Chairman Grant Shapps said: “Britain deserves a vote. It’s been nearly 40 years since the British people last had their say on Europe. People feel the EU is heading in a direction they never signed up to.

“That is why Conservatives want to give Britain a clear vote – in or out – before the end of 2017, after a full renegotiation. A draft Bill to make this happen will soon be debated by MPs – but, crucially, it needs the support of other political parties to pass. Britain needs everyone to build public pressure on this. That’s why we are launching LetBritainDecide.com today: to give people a voice, and to urge MPs to listen to their constituents.”

Liberal Democrats and Labour both oppose the measure – although some Labour backbenchers including Ronnie Campbell (Lab Blyth Valley) and Grahame Morris (Lab Easington) have joined a pressure group called Labour for a Referendum, which is urging Labour leader Ed Miliband to back a poll.

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