Cameron sets out red lines and warns against more European integration

He spent the day in talks on stepping up economic surveillance to prop up the euro and restore growth and jobs to Europe.

He made time too for private talks with some of his EU counterparts, most of whom he had never met.

He insisted that Britain under the new coalition would play a "positive, active, and engaged" EU role.

But before returning to London after resisting Brussels's efforts to "peer review" the Chancellor's annual Budget, he also said it was necessary to stay "on guard" against further integration.

"Of course there are those in Europe who want to progress towards greater integration

and seek treaty changes to bring it about," the Prime Minister said.

"But now Europe is so much wider and broader, with the countries of eastern and central Europe as members, that will help push us in a more intergovernmental direction... the wider and broader Europe takes some of the pressure off further integration – but you also have to be on your guard."

Asked if his euroscepticism had been tempered by yesterday's meeting Mr Cameron said: "There are things we can do at the EU level that are important and in British interests – even my most eurosceptic colleagues would agree.

"I strongly believe that where there is political will in Europe, Europe is strong.

"Where I am entirely at one with my party is that Europe should be about political will and should not be about endless institution building and new rules and new processes.

"We should be doing things, rather than building new structures to talk about doing things."

Apart from insisting that Britain would not submit its Budget programme to Brussels in advance, Mr Cameron also insisted that proposed hefty sanctions against countries breaching deficit and debt limits set by the EU must apply only to the single currency member states.

Mr Cameron and Chancellor George Osborne both made clear before the summit that the Government was fully behind post-economic crisis plans for better co-ordination of national efforts to get deficits and debt down and boost growth and jobs. But where economic sovereignty is under threat, the co-operation stops.