David Cameron details what European Union reforms he wants in speech

Chance to boost prosperity rather than ‘Mission Impossible’.

Britain’s prime minister appealed to doubters at home and in other EU capitals to back his attempt to reform the 28-member bloc as a chance to boost prosperity rather than write it off as ‘Mission Impossible’.

David Cameron, under pressure after overseeing what critics see as a lacklustre start to the renegotiation of Britain’s ties with the European Union before a referendum, used a speech to offer the most detail yet on where he wants change.

The EU executive was quick to call at least one of the British leader’s demands, a limit on benefits EU migrants to Britain are entitled to, “highly problematic”, while saying other proposals such as boosting the role of national parliaments in decision-making in the bloc appeared feasible.

Cameron left little room for doubt that he wants Britain to stay in a reformed European Union, for the first time linking British security to its membership.

However, he also warned that if his demands fell on a “deaf ear”, he could lobby to leave.

“There will be those who say, here and elsewhere in the EU, that we are embarked on ‘Mission Impossible’,” Cameron told diplomats, reporters, and business leaders at the Chatham House think tank in London.

“I do not believe so for a minute... The European Union has a record of solving intractable problems... In doing so, we can make Britain and the whole of Europe safer and more prosperous for generations to come.”

Shortly afterwards, Cameron addressed ‘Dear Donald’ in a letter to Donald Tusk, president of the European Council, setting out his four main objectives to launch what he called the renegotiation’s “formal phase” before a December summit when EU leaders will hammer out the details of Britain’s new terms.

Tusk said in Brussels that negotiations with the other 27 governments would start next week.

In his speech, Cameron spelled out what he wanted from Brussels. In one of the most contentious points, he proposed that people coming to Britain from the EU must live in the country for four years before qualifying for state benefits.

EU members, especially in eastern Europe from where hundreds of thousands of people have left for Britain over the years, complain such a move would be discriminatory.

Cameron said he was “open to different ways of dealing with this issue”.

Cameron’s calls for financial and economic safeguards for countries outside the 19-member eurozone and for Britain to be excluded from the principle of “ever closer union” may also be difficult, the EU said.

Both could require treaty change, which would be almost impossible to complete in two years and would mean several EU states would have to hold referendums, which are increasingly difficult as European politics turn increasingly eurosceptic.