David Cameron: 'Britain better off outside treaty' Reuters

Britain is facing isolation in Europe after David Cameron vetoed a revision of the Lisbon treaty, prompting a majority of EU members to agree to draw up their own deal outside the architecture of the union.

In one of the most significant developments in Britain's 38-year membership of the EU, the British prime minister said early on Friday morning he could not allow a "treaty within a treaty" that would undermine the UK's position in the single market.

The move marked a victory for Nicolas Sarkozy, who had been pressing for an inter-governmental agreement among the 17 members of the eurozone to underpin tough new fiscal rules for the single currency. "We could not accept this," he said of Cameron's demands.

The French president, who has been pressing for the formalisation of a "two-speed Europe", was pleased on Friday when the number of EU member states indicating their support for a separate treaty reached 23. Britain was joined by Sweden, which rejected euro membership in a referendum, the Czech Republic and Hungary.

Angela Merkel, the German chancellor, who had hoped to agree a revision of the Lisbon treaty, said she believed the accord would stabilise the euro. "I have always said, the 17 states of the eurogroup have to regain credibility," she said. "And I believe with today's decisions this can and will be achieved."

Cameron wielded the British veto in the early hours of the morning after France succeeded in blocking a series of safeguards demanded by Britain to protect the City of London. Cameron had demanded that:

• Any transfer of power from a national regulator to an EU regulator on financial services would be subject to a veto.

• Banks should face a higher capital requirement.

• The European Banking Authority should remain in London. There were suggestions that it might be consolidated in the European Security and Markets Authority in Paris.

• The European Central Bank be rebuffed in its attempts to rule that euro-denominated transactions take place within the eurozone.

Sarkozy, who had faced criticisms on Thursday evening that he was isolated after claiming that Britain was pushing for a complete opt-out from financial regulations, rejected the demands out of hand.

Cameron defended his decision to wield the British veto on the grounds that eurozone members could have used the institutions of the EU to undermine Britain's interests in the single market without his safeguards. Speaking at 6.19am local time, he said: "I said before I came to Brussels that if I couldn't get adequate safeguards for Britain in a new European treaty then I wouldn't agree to it. What is on offer isn't in Britain's interests so I didn't agree to it.

"Of course we want the eurozone countries to come together and to solve their problems. But we should only allow that to happen inside the European Union treaties if there are proper protections for the single market and for other key British interests. Without those safeguards it is better not to have a treaty within a treaty but to have those countries make their arrangements separately."

Cameron acknowledged there were risks in striking out alone. But he said Britain would protect its position by insisting that the institutions of the EU could not be used to enforce the new fiscal rules.

"While there were always dangers of agreeing a treaty within a treaty, there are also risks with others going off and forming a separate treaty. So we will insist that the EU institutions – the court, the commission – that they work for all 27 nations of the EU. Indeed those institutions are established by the treaty and that treaty is still protected."

Cameron indicated that Britain may go further and block the use of EU institutions if eurozone countries club together to shape financial regulations and labour laws.

The decision by Cameron will transform Britain's relations within the EU. Other projects, such as the euro and the creation of the passport-free Schengen travel area, have gone ahead without British involvement. But it is the first time since Britain joined in 1973 that a treaty that strikes at the heart of the workings of the EU will be agreed without a British signature. Britain signed the 1991 Maastricht treaty after winning an opt-out on the single currency and the social chapter.

Cameron will be able to tell eurosceptic backbenchers he refused to sign a treaty that would have undermined British interests. But some eurosceptics may say the new treaty marks a major change in the EU and that the British people should be consulted in a referendum.

Sources in Brussels say Cameron is playing a "dangerous game" because financial service regulations are decided by the system of qualified majority voting in which Britain does not have a veto. Britain can form a "blocking minority" at the moment to stop harmful legislation. But this will shrink as more countries join the euro.

Nick Clegg may face questions from pro-European Liberal Democrats about Britain's new four-strong alliance in the EU. Some of the countries that have indicated they cannot support the new treaty may change their minds.

The summit also agreed that:

• Eurozone countries will provide up to €200bn in extra resources to the International Monetary Fund to help countries in difficulty.

• The eurozone's two bailout funds, the European Stability Mechanism (ESM) and the European Financial Stability Facility (EFSF), will be managed by the European Central Bank.