Attempts by party chiefs to paper over cracks ahead were in disarray after interventions from Kenneth Clarke, the former chancellor; John Major, the former premier, and Peter Temple-Morris, a senior backbencher.
Mr Clarke will confirm today that he threatened to resign from the Cabinet before the general election if Mr Major hardened his position on the European single currency.
At the same time, Mr Temple-Morris, MP for Leominster, writing in this paper, describes Mr Hague's position on monetary union as "frankly untenable", and appeals for him to support Labour on constitutional reform.
But Mr Major, writing in today's Sunday Telegraph, argues against joining EMU in 1999 or for the "forseeable future". He says: "It is clear to me that now is not the time for Britain to be joining European Monetary Union. We should have the courage to say no."
The ideological clash will alarm party managers, anxious to present a united front this week in Blackpool. At conference fringe meetings, Euro-sceptics are expected to exacerbate the European split.
Tonight, on Channel 4's Bye Bye Blues, presented by Andrew Rawnsley, Mr Clarke, asked whether he threatened to quit over monetary union, replies: "The Prime Minister knew perfectly well that I would resign if we moved the policy from where it had been settled by the whole Cabinet."
He implies that right-wing ministers, known as "the bastards", were leaking Cabinet proceedings: " What destroyed collective discussion in Cabinet was persistent, systematic leaking. It was not one person. There were three or four."
Mr Temple-Morris's comments underline the left's discontent by attacking the leadership on a range of issues, including the decision to rule out a single currency for 10 years.
The MP described the party's position as "sad" and potentially "disastrous for the party's future", adding: "New Labour has expanded into New Labour, New Britain, and the message is getting home."
On Europe he argues: "Our position on the single currency, committing us to 'Never, but never say never, so let's say 10 years' is frankly untenable. It is not enough to sit back and say we are in opposition... We have to get back into government first, and fighting the next election against a single currency will not help."
Last week the Shadow Cabinet reaffirmed its position on the single currency, although backbench MPs may be given a free vote. On devolution, Mr Temple- Morris attacks Mr Hague's position, arguing: "Just saying 'no' has done nothing for the Conservative position in Scotland or Wales. These measures should be seen as presenting a great opportunity."
Pro-European Conservative MEPs are alarmed at the party's drift to the right on Europe and concerned that new electoral machinery may cause them to be deselected. They also fear they may be asked to fight the 1999 Euro-elections on a sceptic ticket. That raises the prospect of a splinter group of pro-Europeans contesting on their own platform.
There was more bad news for Mr Hague from an ICM opinion poll published in today's Observer, which shows that, while 90 per cent of the public believe that Tony Blair is a strong leader, only 21 per cent grant Mr Hague the same accolade.
Among Tories, Mr Hague ranks below several of his colleagues for leadership, including Mr Clarke.Reuse content