British Prime Minister Mr Tony Blair ducked the euro question yesterday as the Conservatives challenged him to put his "private and bitter debate" with Chancellor Gordon Brown into the public domain, writes London Editor Frank Millar.

The challenge from Tory MP Mr John Redwood came as the all-party Treasury Select Committee appeared to bolster Mr Brown's reported determination to rule out British membership of the single currency for several years.

It also coincided with the latest YouGov survey for the Daily Telegraph suggesting the Blair government will find it impossible to win a referendum on joining the euro for the foreseeable future. Sixty-two per cent declared themselves likely to vote against British membership in any early referendum, as opposed to 28 per cent in favour, in a poll finding overall that Mr Blair's government has failed to shift British public opinion behind its pro-European position.

Ahead of Mr Blair's sixth anniversary in power, the YouGov poll confirmed a remarkable stability in British attitudes to the European Union in the years since the 1997 general election, with 34 per cent considering the EU a "good thing" and almost as many (32 per cent) regarding it as "a bad thing." While only minorities favour either a "fully integrated Europe" or "complete withdrawal", an increasing number (30 per cent) say they are in favour of "a less integrated Europe amounting to little more than a free trade area".

The widespread belief at Westminster is that Mr Brown, with Mr Blair's backing, will shortly declare the conditions for joining the euro not yet met when he announces the outcome of the Treasury's assessment of his famous five economic "tests." However, with the language to be used in ruling out membership still the subject of tense debate between the prime minister and his chancellor, pro-European Labour MPs are fighting a rearguard action to weaken the Treasury's grip on any subsequent decision and to keep alive the possibility of a referendum during the life of the present parliament.

European Commissioner and former Labour leader Mr Neil Kinnock yesterday declared himself confident that this remained "the strongest likelihood."

However, the select committee, while offering no clear recommendation, appeared to strengthen Mr Brown's desire to defer any referendum to a third Labour term by suggesting that a "rolling" assessment of the economic tests could create uncertainty and damage the economy.

Seizing on this Mr Redwood said: "It is high time the prime minister and the chancellor made their private and bitter debate about the euro public. As they are unable to agree on a date or conditions for a referendum they should put British business out of its misery and tell us there will be no referendum before the general election."

At his Downing Street press conference, Mr Blair refused to speculate on how he might keep the option of a referendum open this side of the election without creating economic uncertainty. He also declined to say if he would consider his premiership a failure if he had failed to take the UK into the euro zone by the end of it.