David Cameron faced a broadside from across the Channel as politicians on all sides queued up to warn over his blueprint for Britain's future in Europe.
However German Chancellor, Angela Merkel, held out an olive branch despite an earlier lukewarm reception from German foreign minister, Guido Westerwelle. Mr Westerwelle left the door open to discussions but warned that the UK couldn't "cherry pick" which policies to follow.
David Cameron announcing his referendum plans
Mrs Merkel went further, saying that she wanted to achieve a deal with Britain but warned that any compromise would have to be fair to the other 26 members of the bloc.
"Germany, and I personally, want Britain to be an important part and an active member of the European Union," She told Reuters reporters.
"We are prepared to talk about British wishes but we must always bear in mind that other countries have different wishes and we must find a fair compromise. We will talk intensively with Britain about its individual ideas but that has some time over the months ahead," said Merkel.
The German intervention gave tentative backing to David Cameron's proposals but French leaders were more scathing in their view of the Prime Minister's speech.
French Socialist foreign minister Laurent Fabius said the British Prime Minister was behaving like a club football player who suddenly announces he wants to play rugby.
He cheekily echoed Mr Cameron's own words by saying France would "roll out the red carpet" to British businessmen quitting the UK in the event of the country exiting the EU.
Last summer Mr Cameron promised to "roll out the red carpet" to French companies leaving France because of austerity-led French tax rises.
Mr Fabius went on French radio after Mr Cameron finished speaking and said: "We are like a football club, and if you want to join the football club, you can't then say you want to play rugby."
For those preferring a culinary metaphor, Mr Fabius resorted to a familiar French complaint that the British wrongly believe they can choose from an "a la carte" menu as EU members. They cannot, he insisted - everyone has the set menu.
Mr Fabius also warned that Britain would find life "difficult" outside the EU.
German Chancellor, Angela Merkel
Former Belgian prime minister and Liberal Democrat leader in the European Parliament Guy Verhofstadt accused Mr Cameron of "playing with fire" over EU membership and warned against trying "hold the EU to ransom".
He said: "By holding out the prospect of renegotiating the terms of Britain's membership of the EU and subjecting it to a referendum, David Cameron is playing with fire. He can control neither the timing nor the outcome of the negotiations and in so doing is raising false expectations that can never be met."
He continued: "His speech was full of inconsistencies, displaying a degree of ignorance about how the EU works. He claims he wants a common set of rules for the single market at the same time as wanting exceptions for Britain.
"He wants a single market council to focus on raising competitiveness, but we already have one. He claims that Europe offers more of the same and never changes, but the EU is constantly changing.
"It is the Conservatives' conservative attitude to Europe that perhaps needs to change and recognise that in the 21st century, member states wield greater influence by sticking together and acting together."
Mr Verhofstadt, who heads the European Parliament political group containing Lib Dem Deputy PM Nick Clegg's 12 MEPs, said: "There can be no question of individual renegotiation or opt-out by a single member state from agreed policies. To do so would precipitate the unravelling of the internal market as other countries sought their own concessions in return.
"Mr Cameron will not succeed if he attempts to hold his European partners to ransom."
Mr Verhofstadt said the PM's problem is the internal rift within his own party, suggesting he seems to be jeopardising the interests of his own country for internal party stability.
"The one positive effect of today's speech is the genuine debate that is finally taking place about the EU and Britain's place in it."
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