One of the few certainties in recent years about the euro debate in Britain — that a big majority of the country's citizens were firmly opposed to scrapping the pound — seems to be unravelling.

If sustained, that could be a key factor, say economists, in determining whether Prime Minister Tony Blair plucks up the courage to hold a referendum on entry in the current parliament.

Two opinion polls in recent days have shown a definite warming toward eventual — but not immediate — membership of Europe's single currency project.

Last week's Eurotrack poll from investment bank Barclays Capital, carried out by pollsters NOP, showed a distinct softening of opposition to the euro since notes and coins were smoothly launched in the 12-country eurozone on January 1.

Of the 2,000 people surveyed, 40 percent said they would vote "yes" in a referendum if the government recommended signing up, while only 39 percent said they would vote against. It also showed opposition to immediate entry down to 56 percent from about 70 percent much of last year.

Another poll released this weekend, carried out by Mori for another investment bank, Schroder Salomon Smith Barney (SSMB), came to a similar conclusion.

When questioned about immediate entry, those against fell to 51 percent from 57 percent last October, while those in favour jumped to 33 percent from 26 percent last time. When asked how they would vote if Blair's government was strongly urging that people back entry, the pro vote jumped to 39 percent this month and the anti vote slumped to 47 percent.

SSMB, which has been carrying out its euro poll since 1997, previously put the chances of a referendum being held between 2003 and 2005 at only about one-third. Its latest poll has led it to raise that estimate to 40 to 45 percent. The level of support is now back at levels not seen since early 1999, when the euro was launched and was much in the news.

Support subsequently faded as the euro faded from the news and as the new currency stumbled on foreign exchanges. So is there not a danger that support will fade along with the euphoria over the successful launch of notes and coins?

"I don't think so. This is a genuine change of opinion and it will build as people go on holiday and get to grips with the new money," said Graham Bishop, formerly an analyst at SSMB who now runs his own pro-euro consultancy. "People are waiting for a lead from Blair and it is important he provides it," he added.

Blair's government is in favour in principle of joining but has promised to hold a referendum if it decides the economic conditions for joining have been met. It has set five economic tests — ranging from convergence with the eurozone's economy to the impact on jobs and investment — which will be assessed by mid-2003.

If they are met, Blair would likely hold a referendum very quickly in order to be able to complete the process of joining before the next expected general election in 2005.

There is little doubt the government, which had been expecting the launch of notes and coins to soften up public opinion and which has adopted a decidedly more euro-friendly tone in recent weeks, will be pleased by the latest poll results.

If an EU conference on the future of Europe, which starts in March and lasts a year, meets British concerns about the scope and direction of European integration, it could give Blair an important springboard for a May referendum.