Anxious Liberal Democrat leader Nick Clegg ruffled feathers within the Con-Dem coalition yesterday by accusing many Tory MPs of "openly flirting" with the idea of leaving the EU.

He confessed: "The day I dread - the day I hope never comes - is a time when it is all too late and Britain has stumbled out of the EU."

Mr Clegg claimed that leaving the EU would be "economic suicide."

He made a speech condemning the "ludicrous myth-making" of Euro-sceptics and wrote an extraordinary pro-EU letter appealing to over 100 organisations covering business, trade and the environment. He even sent the letter to policing organisations and charities which combat human trafficking.

"Express your support for staying in the EU however you like," he declared. "Tweet, put it on Facebook, post it on our website, write to the government, write to the newspapers."

He warned: "The isolationist forces in Britain are on the rise - Ukip on the doorstep, Conservative politicians at their conference."

Mr Clegg claimed the Lib Dems would be in favour of a future referendum when there was a "serious change" in EU rules, but he dismissed Prime Minister David Cameron's promise of a vote by 2017 as "a date chosen for internal party management."

No2EU spokesman Brian Denny hit back, accusing Mr Clegg of supporting corporate globalisation while presenting it as "internationalism."

Mr Denny said: "Real internationalism is supporting democracy around the world, but what the EU is doing is removing democracy
and self-determination across Europe.

"With the EU now demanding the privatisation of postal services and rail networks across Europe working people are increasingly aware of the reality of EU membership, permanent austerity and privatisation."

Mr Denny warned that Labour's failure to promise a referendum "will guarantee that it will lose the next election."

Anti-EU Tory MP John Baron said the Lib Dems "do not trust people to have their say on our continued membership.

"They promise a referendum at general elections, but then conveniently forget when in government."

Maverick Tory backbencher Adam Afriyie upset Mr Cameron at the weekend by demanding an in-out EU referendum before the next election.