Cameron's Conservatives table EU referendum bill

It has the support of Prime Minister David Cameron but will not be tabled as a government bill because of the coalition agreement with the pro-European Liberal Democrats.

The question to appear on the ballot papers is “Do you think that the United Kingdom should remain a member of the European Union?"

The radical step is the latest indication that Britain is on the verge of opening the EU's exit door. It also comes as Cameron attempts to face down a rebellion from around 60 Conservative MPs angry that the Queen's speech, which sets out the government's legislative priorities for the next year, does not include provisions for a referendum.

Many are also concerned that Cameron's renegotiation plans are predicated on winning the next election expected to take place in 2015.

The opposition Labour party has so far refused to match Cameron's referendum promise. But its MPs include a vocal minority of eurosceptics and the party is anxious not to be out of step with public opinion.

Cameron in January set out plans to rewrite the terms of the UK's EU membership and then hold referendum in 2017.

However, he has come under sustained pressure from within his own party, and from the anti-EU UK Independence party (Ukip) to bring forward the vote.

Conservatives are also struggling to stave off the rise in popularity of of Ukip. Led by MEP Nigel Farage, the party made big gains at local council elections earlier this month, picking up over 100 seats and beating the Tories into third place with an estimated 24 percent of the vote.

Opinion polls indicate that Ukip would pick up over 15 percent in a general election, the party's highest rating since its creation in the late 1990s.

For his part, Farage dismissed the Tories' referendum bill as "nothing more than gesture politics".

At the weekend two Conservative cabinet ministers, Phillip Hammond and Michael Gove, broke ranks indicating that they would support withdrawal from the EU on the basis of the current terms of membership.

UK media have indicated that at least nine senior ministers would favour a "No" vote without a successful renegotiation.

Key Conservative demands are likely to include special treatment of the City of London financial sector and an opt-out from employment and social affairs legislation.

Meanwhile, the first results of the UK government's 'balance of competences' review, which includes more than 30 audits across a range of EU policy areas, are expected to be published in the coming months.