Downing Street has denied that the prime minister is aiming to hold a referendum on euro entry in October next year.

Number 10 issued a swift rebuttal following comments made by George Foulkes, a former Scotland Office minister, who claimed Tony Blair and the chancellor both believe that October 2003 is "probably" the most likely date for a poll.

Downing Street denied that any date had been set and repeated its standard response.

"The position on the euro remains unchanged. There are five economic tests that have to be met and that remains the case," said a spokesman.

Foulkes, who joins the boards of Britain in Europe and Scotland in Europe today, told Scotland on Sunday newspaper he had spoken to the prime minister and Gordon Brown and had formed a "working assumption" that the poll would come late next year.

His comments follow the first signals that the cabinet are stepping up their efforts for a "yes" campaign.

Foreign secretary Jack Straw said last week that a war with Iraq would not upset a 2003 referendum.

Senior cabinet figures are set to speak in favour of the euro for the first time at events during Labour's autumn party conference.

The latest round of euro speculation brought a mixed response from a key union supporter.

TGWU leader Bill Morris called on ministers to focus on public services.

"My position is that only Labour will deliver the single currency. That means a third term Labour government. People's experience at the next election will be based on public services," he said.

"I argue that we should make public services the priority, get the third term, and then address the euro."

Eurosceptics challenged the prime minister to ditch the economic tests and move straight to a referendum which they believed would end in a "no" vote.

"If Tony Blair thinks the euro is a good idea he should just call a referendum and let the voters judge his views. But he will find little support. People realise we do not need to join the euro to be constructive in Europe," said George Eustice of the No Campaign.

"Our economy is doing better than the eurozone's, and giving up control of interest rates would mean a return to boom and bust and lower living standards."

Liberal Democrat Treasury spokesman Matthew Taylor said it was time for the government to come off the fence

"The government has to stop postponing the decision," he said.

"The evidence is that British manufacturing is suffering enormously outside the euro, with the worst manufacturing recession since 1981, and output lower than when the government was elected.

"It is time to stop dilly-dallying and have the debate and the vote."