Westcountry MPs have joined a growing Conservative rebellion over Britain's membership of the European Union.
Up to 100 Conservative backbenchers are expected to register their anger that the Government's plans for the next year do not include a law to enshrine David Cameron's pledge for an in-out vote by 2017.
Some 78 MPs have signed an amendment to the Queen's Speech, which sets out the coalition Government's legislative programme, making clear their frustration.
They include Richard Drax (South Dorset), Ian Liddell-Grainger (Bridgwater and West Somerset), Anne Marie Morris (Newton Abbot), Sheryll Murray (South East Cornwall) and Sarah Wollaston (Totnes).
The amendment states that signatories "regret that an EU referendum bill" was not included in the Queen's Speech.
It came as, unexpectedly, David Cameron will today publish a draft bill aimed at writing into law his commitment.
The Prime Minister’s move will deepen coalition divisions over Europe, with the Liberal Democrat wing of the Government “nonplussed” about the plan.
Foreign Secretary William Mr Hague said a Private Member's Bill was a "much more difficult route for legislation" than a Government Bill but insisted it meant there could be a vote in the House on the referendum policy.
He told the BBC Radio 4 Today programme: “There can’t be, in a House without a Conservative majority, any certainty of passing legislation. There can be an effort to do so.”
Asked if he was relaxed about Tories voting in support of the amendment, Mr Hague said. “Yes, that remains the position and I must stress that this Bill doesn’t alter that position. Its purpose is not to alter that position. It’s to provide an opportunity."
Sarah Newton, MP for Truro and Falmouth and deputy chairman of the Conservative Party, backed the Prime Minister's position, saying she would support the Bill and arguing Mr Cameron had "delivered".
Cornwall MP George Eustice, who leads a group of Eurosceptic Tory MPs, said colleagues should "get behind" the Prime Minister, contending a "semantic argument" about timing is a "distraction".
Asked what he would do if given an in-out vote today, Mr Liddell-Grainger said: "I would come out. I'm sick to death with it. It's bankrupt. It's pushing us to do things we don't want to do. It's a dictatorship from Brussels."
Mr Cameron's plan is to renegotiate Britain's relationship and stage a referendum on the renewed deal if the Tories win the next election. But he is unable to bring forward government legislation to enact his pledge because of opposition from the Liberal Democrats.
As to whether the amendment would help or hinder Mr Cameron, Mr Liddell-Grainger said: "I don't think we really care. Our job as backbenchers is to represent the feelings of our constituents. And Bridgwater and West Somerset is sceptical – to various levels."
Mr Liddell-Grainger said he would rather a referendum this side of the election, or hold the two on the same day in 2015. He questioned whether a re-negotiation would work without a clear list of demands over powers to be repatriated, and a deadline for them to be delivered. He added: "I would love to renegotiate, but the history of the EU is that it does not like to renegotiate."
The vote is expected take place tomorrow, although Labour and Liberal Democrat opposition means it is certain to fail.
Conservative ministers have been told that they can abstain. At the weekend, Cabinet ministers Michael Gove and Philip Hammond said they would quit the EU if there was a vote today, but stressed that they supported Mr Cameron's bid to renegotiate.
Explaining her backing for the amendment, Mrs Murray said: "It doesn't matter what we promise. The public just don't believe us. I believe we should show the public we are absolutely determined to do this."
Given her concerns over the Common Fisheries Policy and the continuing crisis in the Eurozone, Mrs Murray, whose late husband was a fisherman, thought she would probably vote to quit the EU if a vote was held now.
On his blog, Mr Drax wrote the EU is a "huge elephant in the room, which simply won't go away". "It was always foolish of those who didn't want to discuss our future position on Europe to believe it would just conveniently be forgotten," he said. "The EU affects our sovereignty, our liberty and our future. I can't think of three more important topics for politicians to consider and debate, especially in our party."
He said Tory backbenchers were acting because of "lack of clarity, dragging of feet and general waffle from all political parties".
"Unprecedented times needed unprecedented action and I am confident that a large number of my colleagues will vote for this amendment," he went on.
Mr Eustice, Conservative MP for Camborne and Redruth and a former Press aide to the Prime Minister, said: "David Cameron set out exactly the right approach towards the EU in January. We should renegotiate our relationship with Europe and then have a referendum after. We now need to get behind him and knuckle down to winning the next election because without a Conservative victory nothing will change. Semantic argument about referendum timing is a distraction from the core task."
Meanwhile, Ed Miliband has come under pressure from his party's backbenches to pledge a referendum in its next manifesto. Senior Labour MP Keith Vaz, former Europe minister, said: "I believe that it is the democratic right of the people to make that decision for themselves." Labour has ruled out a referendum now, but not in the future.
The Lib Dems have not backed the Conservative position. Leader Nick Clegg has said a vote in the next Parliament was "not in the national interest", and would create uncertainty that spooks business.