Former Conservative cabinet minister Michael Portillo has become the latest Tory heavyweight to argue that Britain should leave the European Union - and claims that the Prime Minister is "insincere" in his promise to grant an In-Out referendum.
In an op-ed for The Times, Portillo said he was unsure that the Tories would win the next general election in 2015. "They didn’t win the last one and it is extremely rare for governing parties to improve their share of the vote, even when their opponents are as weakly led as Labour and the Liberal Democrats are now," he said.
Writing in The Times on Tuesday, the former Conservative chancellor Lord Lawson said there was now a "clear" case for withdrawal, insisting the economic benefits would "substantially outweigh the costs".
And he said David Cameron's plan to negotiate a looser relationship with the EU as "virtually impossible" - once again exposing the split within the Tory party over the issue of Europe.
Eurosceptic MPs, emboldened by the succes of Nigel Farage's UK Independence Party, had urged the Tory leadership to include a referendum bill for this parliament in the Queen's speech - but no such legislations was mentioned.
Portillo said he did not agree with Lord Lawson that Labour would be likely to match the Tories' promise of a referendum.
He accused Tory ministers of "whinging" about Europe but being unprepared to back withdrawal. "The default position of the political class is defeatism: the belief that Britain could not survive outside the union; and the political class assumes that the public shares its defeatism."
"I would vote “no” and fervently hope that the British have more guts than those who govern us, and more than those who govern us think we have."
He said the "disasterous" Euro had "created hardship, unemployment and division on a dangerous scale."
"The UK is unhappy in the EU. We do not share its vision, partly because we are not visionary by temperament. We are not so easily convinced that the EU is a necessary response to the horrors of the Second World War because our experience of that war was different. We did not endure revolution, dictatorship or invasion.
"Other countries may look to institutions at the European level because they doubt the durability of national institutions that perished in that conflict. We do not, because ours survived."
Downing Street said the prime minister remained "confident" that his strategy "will deliver results".