British Prime Minister David Cameron said the euro zone debt crisis was less than halfway through, and raised doubts about the future of the single currency in an interview yesterday.

Cameron said the euro zone crisis was partly to blame for Britain falling back into recession, and insisted that getting the economy moving again was the biggest issue for the government, at a time when the popularity of his Conservative Party had fallen to its lowest level since 2004.

"What's happening in the euro zone is a massive tension ... that countries are finding very difficult to adapt to, and that's what we're seeing. So I don't think we're nearly halfway through it," he told the BBC.

"I think it's going to be a very long and painful process in the euro zone as they work out do they want a single currency with a single economic policy ... or are they going to have something quite different," he added.

Countries on the periphery of the euro zone are struggling to implement austerity programmes to reduce the size of their budget deficits, and European Central Bank aid to banks at the turn of the year is not proving a lasting solution.

Britain faces its own challenge to reduce its budget deficit - which is bigger as a share of the economy than any in the euro zone - and Cameron's party has been suffering ahead of local elections taking place across much of Britain on Thursday.

A YouGov opinion poll in the Sunday Times showed that support for the Conservatives had fallen to 29 per cent. The opposition Labour Party had 40pc support.

Cameron said that getting the economy growing again was his top priority, but rejected any loosening of the austerity plan and insisted that a rebalancing of the economy towards export-led growth was taking place, albeit too slowly.-Reuters