Britain's Prime Minister, Mr Tony Blair, has formally abandoned his opposition to plans by France and Germany to form a "pioneering group" of EU states to push towards closer political and economic integration.
Speaking in the southern German city of Tubingen yesterday, Mr Blair said there was no danger of Britain being left behind in a two-speed Europe and he urged his country to see Europe as an opportunity rather than a threat.
"I have no doubt that it is important for Great Britain to be a full and leading partner in Europe," he said. "It is time we had the confidence in Britain to realise we can shape and influence events in Europe and indeed are doing so. Europe is not a conspiracy against us but an opportunity for us." Mr Blair described as "interesting and important" a speech this week in which the French President, Mr Jacques Chirac called for a core group of EU member-states to start co-operating more closely in areas such as economic policy, defence and security, and in fighting crime.
Mr Chirac's speech echoed a call by the German Foreign Minister, Mr Joschka Fischer, for a group of member states around France and Germany to lead the EU towards political unity.
Until now, Mr Blair has been sceptical about the idea of "reinforced co-operation" between member states, fearing it would create a two-speed Europe. But during talks with the German Chancellor, Mr Gerhard Schroder, in Berlin on Thursday, he agreed to drop his outright opposition to it.
A German government spokesman said the two leaders discussed Mr Chirac's speech and had reached a number of common positions.
Apart from "reinforced co-operation", the French President proposed a written constitution for Europe that would define the powers of nation states within the federation.
Critics of the Franco-German proposal for reinforced co-operation complain it is still unclear what form such co-operation might take and it became clear yesterday that France's Socialist government has strong reservations about Mr Chirac's vision. The French European Affairs Minister, Mr Pierre Moscovici, explicitly disowned Mr Chirac's speech, which the government fears could overshadow its six-month EU presidency.
"That is not a speech by the French authorities. It was the President's speech," he said.
Mr Moscovici warned that overloading the agenda of the current Inter-Governmental Conference could endanger the structural reforms Paris hopes will be agreed at a summit in December.
"Let's not add to this right now debates that are important but we know we cannot deal with. We will not write a European constitution during our presidency. We will not achieve a federation of nation states during our presidency. We will not institute new federative sovereignties," he said.
Mr Chirac's spokeswoman responded sharply, declaring that the President, who has primary responsibility in the area of foreign affairs, was speaking in his official capacity.
"France speaks with one voice and the French presidency of the European Union makes this all the more necessary," she said.
Austria's chancellor, Dr Wolfgang Schussel warned yesterday that the creation of a core group of member states within the EU could endanger the interests of smaller states and lead to a new hegemony within Europe.
Mr Blair's U-turn on reinforced co-operation came after Mr Schroder told him that if Britain blocked a move towards flexibility at December's summit, a core group could be formed alongside the structure of the EU. A precedent for this already exists in the shape of the Schengen agreement, which removed border controls between some EU member states.
Britain is likely to work with other sceptical member states, including Ireland, to impose conditions on reinforced co-operation. These could include a requirement that at least half the EU's 15 member states must support any move towards such co-operation, which would be limited to specific policy areas.