The new European constitution is not expected to be endorsed by parliament until early next year in a new signal that Tony Blair wants to delay confronting public scepticism.
Whitehall insiders said the bill to ratify the constitutional treaty and pave the way for a referendum was not now expected to become law until December or January, as the Tories gear up to challenge the government in parliament. The legislation will be published this week or next. But Foreign Office officials had originally been pressing for the bill to have its first reading before Christmas so it would reach the statute book before the general election expected in May.
They had wanted to avoid a parliamentary clash overshadowing Britain's EU presidency in the second half of the year.
The prime minister has promised repeatedly to make the case for Britain's place in Europe but pro-European campaigners feel frustrated at what they regard as procrastination on his part.
Pro-Europeans admitted the government faced a huge challenge in parliament and in the country, with opinion polls showing a majority likely to oppose the constitution in the referendum.
Ian Taylor, a pro-European Tory MP, said Mr Blair should not have agreed to a referendum. “Because Blair's not been robust enough, because he's been dilatory and because he's held back, he's got this curse hanging over him,” he said.
A senior Conservative official said his party would vote against the bill on the grounds that while it favoured an early referendum it vehemently opposed the constitution. “We will give them hell over the constitution,” he said.
The referendum is expected to be held in May or June next year. The bill will include the text of the question to be put to voters.
As the Financial Times revealed last month, the question is expected to be: “Should the United Kingdom approve the treaty establishing a constitution for the European Union?”
Neil O'Brien, campaign director of Vote No, the anti-constitution lobby, said his supporters would be “using the parliamentary focus to tease out the issues”.
Meanwhile Lucy Powell, campaign director of Britain in Europe, which is in favour of the treaty, welcomed the opportunity to dispel eurosceptic myths before the referendum campaign began.
“In terms of winning the referendum, the main problem is there's almost complete ignorance and lack of awareness of the issues,” she said.
Ms Powell also suggested that parliamentary hostility to the bill would be tempered by a number of pro-European Conservative peers such as Lord Howe and Lord Brittan.