Ken Clarke believes that UK membership of the euro will benefit future Conservative governments.

In a BBC interview, the former Tory chancellor said that campaigning for a "Yes" vote in a future referendum on the single European currency was, for him, a more immediate concern than securing a Conservative government.

Clarke, a noted europhile, is expected to play a leading role in a referendum, hoping he can help persuade moderate Conservatives to give their backing to Britain's entry to the euro-zone.

Asked what his priority was, Clarke told the BBC's Breakfast with Frost: "I think to join the euro to prepare the base for a Tory government in 2005-2006 in my opinion."

"I think if we can rid the Conservative Party of its neurosis on this subject and if we can provide a sound basis for Britain's role in the world and Britain's best economic prospects inside the single market then the next Conservative government will be more successful," he said.

Clarke, who last week backed a pro-European campaign group, said he had not told the party leadership of the relaunch of the Conservative section of the European Movement.

"I didn't speak to Iain Duncan Smith. I only had the one article [in the Times] because by and large, rather remarkably since he took over, Iain Duncan Smith and I have had a sort of unspoken pact that neither of us will go on too much about the euro,'' he said.

"We will try to get the Conservative Party back to reality and thinking about something else most of the time."

And the former chancellor backed speculation that Gordon Brown was ready to give his support to a euro-referendum next year.

"I think Gordon Brown, Tony Blair, Charlie Kennedy and I are all saying there will be a referendum next year and we will be asking people to join the single currency if the economic conditions have come right by then.

"The fact that Gordon always looks a bit gloomy and scowls a bit when he says it doesn't necessarily mean he has ever been on a particularly different wavelength," said Clarke.