Proposed changes to the way the euro zone governs its fiscal policy do not require a referendum in Britain, which is in the EU but does not use the single currency, the government said on Monday.

European leaders are under pressure this week to deliver a lasting solution to the euro zone debt crisis, with proposals to create a closer fiscal union based on tougher economic policy rules at the heart of discussions ahead of a summit on Friday.

Under British law, the Conservative-Liberal Democrat coalition government is required to hold a referendum on any European Union changes that result in a big switch of power from London to Brussels.

No one is proposing a significant transfer of power from the UK to the EU. No one has put that on the table and I don't think it's likely to be on the table, Prime Minister David Cameron's spokesman told reporters.

What's being talked about is a new set of rules for the euro zone and how those countries that are members of the euro zone organise themselves on fiscal policy. There's no proposal on the table for a transfer of powers from the UK to Brussels.

Some in the Conservative party, which has a strong eurosceptic wing, have called for a referendum even on changes that only affect the 17 nations which use the euro, arguing that the 10 non-euro nations could still be inadvertently affected.

Cameron himself has warned there is a risk that a closer-knit euro zone could pose problems for Europe's single market in the future and analysts say the 17-strong bloc could vote as one to force through changes against the will of other EU members.

Britain, fearful that a prolonged crisis will drive its own economy into recession, has joined those voices calling for a closer fiscal union in the euro zone even if that means different problems arising further down the line.

Work and Pensions Secretary Iain Duncan Smith, a leading Conservative eurosceptic, said on Sunday he expected a referendum to be held in Britain if there is an additional surrender of sovereignty from us to the European Union.

His intervention came just weeks after members of parliament debated whether to hold a referendum on Britain's membership in the European Union.

Cameron, wary of the damage done to previous Conservative leaders by eurosceptic rebels, has told his party that Britain belongs in the EU - its biggest export market - but that there will be opportunities to claw back powers from Brussels.

(Reporting by Matt Falloon; Editing by Peter Graff)