Eurozone crisis: PM 'may refuse to sign EU treaty'
David Cameron has said he will not sign any reworked EU treaty designed to solve the eurozone crisis if it does not contain safeguards to protect British interests.
The prime minister said there must be protection for the single market and the UK financial services sector.
The EU treaty may be rewritten to achieve greater fiscal integration within the eurozone.
But that would require the agreement of all 27 members, including the UK.
Meanwhile, Deputy Prime Minister Nick Clegg has told BBC Radio 5 Live that the "hand on the clock is moving to the 59th minute" in the eurozone crisis.
Germany and France are developing a plan for greater fiscal integration among the eurozone's 17 members ahead of a crucial meeting on Friday.
Mr Cameron said he would be there "to defend and promote British interests", but stressed that the most important thing for Britain right now was to resolve the eurozone crisis.
"If they choose to use the European treaty to do that then obviously there will be British safeguards and British interests that I will want to insist on, and I won't sign a treaty that doesn't have those safeguards in it."
He added: "As long as we get those then that treaty will go ahead. If we can't get those, it won't."
Later, in an article for the Times, Mr Cameron wrote that the 17 eurozone countries could decide to reach agreement on their own, but "Our colleagues in the EU need to know that we will not agree to a treaty change that fails to protect our interests."
Some observers have argued that a treaty of 17 states "would be more effective if it had access to the institutions of the EU such as the European Court of Justice and the Commission," the article says.
"These institutions belong to all EU states and their use outside the treaty would clearly require safeguards."
"Our asks will be practical and focused. But eurozone countries should not mistake this for any lack of steel."
Downing Street has said that none of the proposed changes being discussed would trigger a referendum in the UK as they would not constitute a significant transfer of power from Westminster to Brussels.
The measures under consideration are about how the eurozone countries organised and governed themselves, it has claimed.
But many MPs say an agreement involving just the 17 members of the eurozone would alter relations with the EU as a whole and a referendum was needed.
Mr Clegg said the collapse of the euro would be "a complete cataclysm" for the whole of Europe.
"There is real urgency to it... we need a clear roadmap towards new rules in the eurozone, to make sure the currency is buttressed by great fiscal intervention," he said.
"That might need some kind of treaty revision here or there... that will take several months to thrash out. But what everyone is looking for is a basic roadmap for the future of the eurozone at the summit at the end of the week."
The last Labour Foreign Secretary, David Miliband, has said tough talk by the prime minister could lead to less influence.
"David Cameron faces a real trap from those in his own party who are spoiling for a fight that would bring Britain out of the European Union," he said.
"The trap is that in the end the other countries will go ahead on their own and not just decide economic policy for the eurozone, they'll end up designing policy for the whole of the European Union.
"And that will put Britain in the second division, a place that it's tried to avoid for the last 40 years."
'Too much Europe'
The prime minister says he will seek to return powers to the UK at the right time but many Conservative MPs want him to go further.
Last month, more than 80 Tory MPs defied the government and called for a referendum on the UK's membership of the EU.
Conservative MP Douglas Carswell, who wants the UK to leave the EU, said EU leaders appeared as if they were trying to solve a problem created "by too much Europe by giving us even more Europe".
"Unfortunately for the political elite, the people are not just going to go away," he told the BBC News Channel.
"We were promised by all three party leaders in the last Parliament that we would have a referendum. Now it does not suit them to do this they have dismissed this as something they can afford to ignore. We need a say over whether the new deal which will emerge from these negotiations is in our national interest or not."