Get off the fence, Prime Minister: David Cameron's caveats on EU vote leaves Tory sceptics fuming

Anti-EU Conservatives vowed to keep up the pressure on David Cameron yesterday after the Prime Minister "opened the door" to a referendum on Europe – without saying when it would be held or what the public would be asked.

The Prime Minister is expected to be challenged in the Commons today by backbench Tories who want an unbreakable promise of a referendum before 2020. More than 100 Tory MPs are understood to have backed a letter sent to Downing Street last week calling for legislation that would commit the UK to holding a referendum after the next general election.

In an article for yesterday's Sunday Telegraph, Mr Cameron tried to reassure the Eurosceptics without offering any concrete promises. "For me the two words 'Europe' and 'referendum' can go together, particularly if we really are proposing a change in how our country is governed, but let us get the people a real choice first," he wrote.

He added that now is the wrong time for a referendum on whether to stay in the EU. His line was echoed yesterday by Mr Hague, who told the BBC's Andrew Marr programme: "The time to decide on a referendum... is when we know how Europe is going to develop over the coming months."

But in a speech today, the former Defence Secretary Liam Fox, who is positioning himself as a future leader of the Tory right, will say that "life outside the EU holds no terror."

Other Eurosceptics complained that Mr Cameron's and Mr Hague's words offered nothing new. John Baron, who organised the letter calling for legislation that guaranteed a referendum, said: "It's encouraging he is talking about a referendum but he has made no firm promise. His tack, that now is not the time for an 'in or out' referendum, is an Aunt Sally. It's time for a proper, informed debate to address the credibility gap with the public.

"The heart and soul of the Conserva-tive parliamentary party and, I believe, the party as a whole believe the country wants and needs a referendum." Mr Baron aims to press his point home in Mr Cameron's report to the Commons on last week's Brussels summit, which he is expected to deliver today.

Nadine Dorries, one of Mr Cameron's most outspoken critics on the Tory benches, said it was unreasonable to expect Eurosceptics to back down "when one week the Chancellor is urging yes to a referendum commitment, soon afterwards the Prime Minster says no and then a day later seems to say something else".

Another Tory MP, Mark Pritchard, said: "Once again, when it comes to Europe, it is always 'jam tomorrow'. But tomorrow never comes."

A Liberal Democrat spokesman said: "Mr Cameron has set out his views as Conservative Party leader about possible referenda following the 2015 elections, which he is entitled to do."

Eurosceptics: leading the pack

Liam Fox: The former Defence Secretary is looking to make a political comeback today with a strongly worded anti-EU speech

John Baron: Claims that more than 100 Tory MPs support his call for legislation that will guarantee a referendum before 2020

Nadine Dorries: Accused ministers of putting out contradictory messages about a referendum which will not persuade the eurosceptics