Tony Blair would take the dramatic gamble of staging a referendum on the single currency on 1 May 2003, under proposals that are being considered in Whitehall.
Pro-euro advisers are pressing the Prime Minister to arrange for the historic vote on abolishing the pound to coincide with elections to English district councils, the Scottish Parliament and the Welsh Assembly.
The idea for staging the "super Thursday" vote as a way of boosting turnout – thereby increasing the democratic legitimacy of a pro-single currency result – has gained ground since the launch of euro notes and coins last month.
However, it would present a daunting challenge to Mr Blair, who would have to overturn hostility to the single currency among millions of voters in a little over a year.
The Britain in Europe (BiE) pressure group, which is expected to lead the "yes" campaign, has already drawn up a strategy plan based on a poll taking place on 1 May 2003.
The possibility of the spring vote was inadvertently revealed by Peter Hain, the minister for Europe, in an interview with a French newspaper last week. He said the Chancellor, Gordon Brown, could take a judgement on whether Britain had met the five economic tests for euro membership as soon as this autumn, with a poll taking place six months later.
Euro-enthusiasts are now focusing on 1 May as the only realistic date in the first half of next year for the referendum.
They think opposition to the euro is soft – with only one-third of voters strongly against the single currency and the rest open to persuasion – and could melt away after Britons return from summer holidays in euro-zone countries. They also believe the higher turnout on a "super Thursday", with the Government calling on the loyalty of Labour supporters, would lift the chances of a "yes" vote.
The former Tory chancellor, Kenneth Clarke, will put more pressure today on the Government to act swiftly on the euro in his first major speech since failing in his party leadership bid in September.
Charles Kennedy, the Liberal Democrat leader, will tell a BiE meeting today: "There is little point the Government dithering on this issue any longer. They need to call a referendum as soon as possible to help jobs, investment and trade."
The BiE "war book", planning for a 1 May referendum, sets out a detailed daily strategy for leading a "yes" campaign beginning in mid-March next year. A draft version of Operation Final Push: isolation or prosperity, seen by The Independent, envisages kicking off with an analysis of how prices for many consumer products are lower in countries with the euro than in Britain.
The feeling that Mr Blair could go to the country early was underlined in an interview this weekend with Charles Clarke, the party chairman, who said that 2002 was "decision year" on the issue. One minister confirmed that calls for a vote on 1 May 2003, were increasing. He said Mr Blair would increase his pro-euro rhetoric during the summer but would only call the referendum if he was convinced he could deliver a victory.
Meanwhile, Lehman Brothers, a US-owned City bank, said there was now a strong chance that a referendum to join the euro would succeed. A "poll of polls" had showed that public opposition to the euro had weakened in the last two years, it said.Reuse content