The public trusts Gordon Brown more than four times as much as Tony Blair to make the decision to enter the euro, a new poll has found.

A YouGov survey for the Telegraph newspaper revealed that the sceptical chancellor has the backing of 55 per cent of voters on the single currency.

The poll came as Blair and Brown delivered a bullish assessment of Britain's euro hopes to the weekly meeting of the Parliamentary Labour Party.

In an upbeat speech to backbenchers, the prime minister said MPs must go out and make the case for membership of the single currency.

But the poll reveals that just 12 per cent have faith in the prime minister's judgement despite attempts this week to present a united front on the government's "not yet" decision.

A third of respondents don't know who they trust - with the results confirming the huge task ahead of Blair if he is to successfully persuade Britain to abandon the pound.

The poll does at least tell the prime minister that in Brown he has a prime asset for any referendum campaign, which could still come before the next election in 2005 or 2006.

But opinion has turned further away from British entry into the euro, with 61 per cent now being opposed compared to a slim majority of 51 per cent a year ago.

Much of that rise may be down to the lack of faith in Blair, whose approval ratings have slumped over claims that he "sexed up" intelligence information in order to build support for the war in Iraq.

In contrast the "iron chancellor's" reputation remains strong and his known euro-scepticism could help the government turn public opinion around if he eventually comes out fighting for a "yes" vote in a national ballot.

Ministers have sought to dress up the "not now" verdict given by the chancellor in his statement to MPs on Monday as the start of a concerted campaign to build support for the euro.

Blair and Brown held a joint press conference on the benefits of the single currency and trade secretary Patricia Hewitt gave a speech in Madrid to the same effect.

The chancellor also attended a breakfast meeting with the pro-euro Britain in Europe group on Wednesday morning.