The Conservatives have published their European Union (Referendum) Act 2013.
The referendum question being promised by David Cameron is: "Do you think the United Kingdom should remain a member of the European Union?"
Cameron has pledged to back a Conservative MP's EU referendum bill, as Cable labelled the move potentially 'damaging' for the country.
114 Conservative backbenchers have voted in favour of a eurosceptic motion to amend the Queen's Speech in defiance of the Prime Minister.
David Cameron has denied he has buckled under pressure from his backbench MPs over the EU debate.