One of the government's keenest euro-enthusiasts has cooled on the prospects of a "risky" referendum on the single currency.

Welsh secretary, Peter Hain, has triggered previous rounds of speculation with past backing for a swift UK timetable to eurozone entry.

But on Sunday he signalled a more "cautious" approach amid indicators that Downing Street has moved back from a euro-vote in this parliament.

"I am not in favour of rushing in," he told the Sunday Times.

"So for me the decision being made this year, or next year, or whenever it might be is not the issue. The timing is not an issue except that it can not be postponed for ever."

This year will be UK decision time for the euro 12 months after the single currency has been introduced on most of mainland Europe.

As 2003 begins the future is not rosy for pro-European campaigners enthusiastic about joining the eurozone.

Dark clouds on the global economic horizon may make a cautious British chancellor even more careful about the single currency following a sometimes bumpy ride in the eurozone during 2002.

High unemployment in Germany and inflationary price rises as traders used the changeover to new notes and coins to mark up goods, may tip the scales against a euro gamble at the polls - especially for a sceptical Gordon Brown.

His five economic tests are the hurdles that must be cleared in June this year if Britons are to get a referendum on the single currency in this parliament.

Hain told the BBC that it was time to "wait and see"

"Let's just wait and see what this economic assessment comes out and then we will decide where we go," he said.

"We believe Britain should be in the euro. That's a political decision we got endorsed at two successive general elections. But it has to be done in the right circumstances."

The cabinet minister - who sits on the EU convention mapping the shape of Europe's future political institutions - appears to have pulled back from his prediction last year that Britain could have scrapped the pound as early as 2005.

"We are determined to get it right. We don't think, I don't believe and never have believed we should rush in madly like for example Michael Heseltine or Charles Kennedy have said, nor that we should rule it out forever as Iain Duncan Smith has said," Hain told the BBC on Sunday.

"Both of those positions are no sense positions. The common sense position is to say 'Yes we ought to be in the single currency in the future but we've got to do it in a careful, cautious, practical fashion which is what we will do'."

The Conservatives have accused Downing Street of political opportunism.

Shadow chancellor, Michael Howard, claimed that Hain's comments "reinforces the impression that the only test that the government is interested in on the euro is whether or not they can win a referendum".

"Labour should stop playing games. Either they should commit to holding a referendum and argue the case for Britain joining the euro, or they should rule out a referendum and concentrate on the real issues facing the British people, such as health and education," he said.