British Prime minister David Cameron said late on Tuesday that he will not sign up to any changes to the European Union (EU) treaty if they were against British interests.

"I won't sign a treaty that does not have safeguards in it around things like the importance of the single market and financial services," Cameron told the BBC in London.

Cameron is worried that any rewriting of the EU treaty, to be discussed later this week, could make an open market for British goods and services more restricted. He is also keen to protect London's status as the financial capital of Europe since receipts from the finance sector account for 11 percent of government tax income.

Britain has more leeway than any of the struggling European economies such as Ireland, Greece or Italy, in dealing with its economic problems because it retains control of its own currency and is not a member of the euro, however the problems of the eurozone have significant impact on the British economy.

The EU is the primary export market for Britain, and the instability in the eurozone has seriously affected business and consumer confidence in Britain, where the economy is already feeling the pressure of chancellor of the exchequer George Osborne's austerity drive across government spending.

Britain's economy is struggling. Several hundred thousand public sector jobs have been lost in Osborne's cuts while youth unemployment is at the million mark. Inflation is above 5 percent but wage settlements are below 3 percent.

In his autumn statement chancellor Osborne had to extend the period for hitting his financial targets by two years, because growth this year is set to be 0.9 percent, against his forecast of 1.7 percent, and growth in 2012 will be 0.7 percent against the 2.5 percent Osborne had based his figures on back in March.

Cameron acknowledged the importance of the eurozone to British hopes of economic recovery. "The most important British interest right now is to sort out the problem in the eurozone which is having a chilling effect on our economy."

"To save the single currency you need more than simply a treaty; you need to address the competitiveness problem, you need to address the deficit problem, you need to take action to convince the markets that you are serious, you need all the institutions of the eurozone, including the European Central Bank, to get behind that," he added.

"I am saying that if European nations choose to use the European Treaty to do that, Britain will be insisting on some safeguards -- if we can get those it will go ahead, if we can't it won't," Cameron continued.

Leaders from the 27 member states of the EU will meet in Brussels on December 8 and 9 to discuss how to resolve the eurozone crisis.

The leader of Europe's strongest economy, Angela Merkel of Germany, has said that she wants member states of the eurozone to agree to far more stringent controls and oversight of their government budgets to ensure compliance with eurozone targets.

This would bring the nations much closer to a fiscal union, and entail a significant loss of sovereignty for eurozone states as well as creating a two tier Europe made up of those nations inside the euro, and another group of those nations outside the euro.

Changes to achieve this could be made by agreement of all 27 members of the EU, through a revision of the European Treaty. Alternatively, the 17 eurozone member nations could create a new treaty of their own.