A heated fringe meeting provided the first confrontation between two former chancellors, Kenneth Clarke and Lord Lamont.
Mr Clarke, unofficial leader of the Tory pro-Europeans, accused Eurosceptics of hijacking the party in the way Bennite left-wingers and CND campaigners took over Labour in the early Eighties. He charged Lord Lamont and other Europhobes with spreading "paranoid nonsense" about the European Union.
Lord Lamont hit back, accusing the pro-EU Tories of having a hidden agenda of trying to take Britain in to a federal Europe "by stealth". He dismissed the comparison with Labour's unilateralists, saying that "name-calling" by his former cabinet colleague would not help the party to have a serious debate.
Mr Clarke, who was occasionally booed and heckled by sceptics in the audience, declared: "I have come to this conference hoping to see that we are not going to repeat in this party the mistake that the Labour Party made in 1979, when people like Denis Healey had to sit and listen to a party taken over by unilateralists and left-wing people who became extremely intolerant to those who couldn't see their ideas." He said William Hague's decision to ballot Tory members on the single currency was "hugely divisive" and the pounds 300,000 cost would have been better spent on the party. The prospect of having "another Euro row made most of the public groan as well as myself", he said.
This prospect, nevertheless rapidly developed into a reality as Baroness Thatcher launched her offensive, endorsing Mr Hague's ballot.
"Keeping our national independence is a great cause and it is one on which the British people can rally," she said, accusing Tony Blair of wanting to "submerge" Britain into Europe. "Moreover it gives the Conservative Party an excellent chance of winning next time."
Old adversary, Michael Heseltine, however, soon took the heat out of Lady Thatcher's remarks in a television interview.
"You have to take Mrs Thatcher really with a cellar-full of salt," he told BBC's Newsnight. "She was the prime minister that signed the single European Act and took us into the ERM ... and deeper into Europe, sharing sovereignty on an unprecedented scale."
Other senior Conservatives joined the fight throughout the day. Former Tory Health Secretary Stephen Dorrell said Mr Hague's stance on the euro, "does not constitute a policy for Europe" while another former cabinet minister Leon Brittan added his weight to the condemnation describing the ballot as "very unwise".
The former prime minister, John Major, appealed to the party to rediscover the "tolerance and unity that made it a formidable political fighting force for the past 300 years".Reuse content