David Cameron's speech promising an in-or-out referendum on EU membership has been met with irritation and outright mockery in Europe.
The prime minister promised a vote in 2017 following a negotiation which would repatriate powers back to the UK and allow for more "flexible" membership.
"It's not our job to worry about what foreign ministers are saying," an aide to Cameron told reporters after PMQs.
"It's our job to worry about what the British people are saying."
But the strength of the reaction from senior EU political figures gives some indication of the obstacles Cameron faces in trying to secure his goal.
"Imagine we are a football club. You join the football club, but once you are in, you cannot say 'let's play rugby'," French foreign minister Laurent Fabius said.
In a comment mocking British attempts to benefit from France's introduction of a financial transaction tax, he added that he recently told a meeting of UK businessmen: "If Britain wants to leave Europe we will roll out the red carpet for you."
Swedish foreign minister Carl Bildt commented: "Flexibility sounds fine, but if you open up to a 28-speed Europe, at the end of the day there is no Europe at all. Just a mess."
Martin Schulz, head of the European parliament, said: "He just wants change in the single interest of Britain and that's not fair."
Guy Verhofstadt, former Belgian prime minister and current leader of the liberal grouping in the European parliament, said: "His speech was full of inconsistencies, displaying a degree of ignorance about how the EU works."
Closer to home, Cameron was also the subject of snide comments and outright opposition.
His coalition partner, Nick Clegg told Sky News: "We should always be governed by what's in the national interest, and my view is that years and years of uncertainty because of a protracted, ill-defined renegotiation of our place in Europe is not in the national interest because it hits growth and jobs."
Lord Mandelson, former EU trade commissioner and British business secretary, told the BBC: "I think other member states will not negotiate such a new settlement as the special state for Britain within the European Union.
"I don't think they will provide a new treaty to accommodate Britain's demands and I don't think they will agree a timetable for negotiation that suits Britain's needs.
"David Cameron will be left rather like a man without a plan."
If Britain is to succeed in renegotiating along the lines Cameron suggested today, it would need a majority of the EU's member states to back a European Convention allowing the EU treaty to be changed.
There will be 27 member states at that point, after Croatia joins later this year, meaning the deal will need the support of 14 countries.
If the convention is passed, the negotiations would drag in all member states, the European parliament, national parliaments and the European Commission. Any treaty change would need to be unanimously accepted.
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