The former Prime Minister used the campaign platform for a referendum on the treaty to deliver the kind of handbagging to her successor not seen since she came back from a European summit and said 'no, no, no' to Jacques Delors.
Lady Thatcher said she signed the Single European Act - which her anti-Maastricht friends regard as a lapse of judgement - because she believed the European Commission would honour its provisions which limited majority voting.
Being British, said Lady Thatcher, she had a right to expect it to be honoured. 'Our trust was not well-founded,' she said. But she could not extend that excuse to Mr Major.
'We got our fingers burnt. The most silly thing to do when you get your fingers burnt is to bring forward a bigger and worse Act which is the equivalent of putting your head in the fire.'
Lady Thatcher said Mr Major was living in 'Cloud-cuckoo-land' if he thought this week's retreat on the Bill was meaningless. She presided over a press conference with David Alton, the Liberal Democrat, and Peter Shore, the former Labour minister, to announce the results of a telephone poll on the Maastricht treaty. A total of 55,000 votes were cast, with 93.5 per cent against the treaty.
Lord Pearson, chairman of the campaign committee, said: 'We are particularly grateful to the Sun newspaper which had it for two months on page two of its organ.'
Having stoutly defended the sovereignty of Parliament, and moved to the unelected chamber, was it not a bit rich to have her pressing for a referendum which took the decision out of the hands of the elected members? Lady Thatcher dismissed any suggestion of hypocrisy on a referendum.
'To say that our power comes only from the ballot box and then we ignore such a big constitutional change seems to me to be utterly wrong,' she said.
'There is only one way to elevate a single issue and give it the importance which this one deserves and that is to have a specific referendum.'
Lady Thatcher would have no truck with European foreign policy, or a federal Europe. 'When Saddam Hussein attacked Kuwait, it did not occur to me to consult the European Community,' she said.
Having led the demands for arming the Bosnian Muslims and bombing the Serbs, Lady Thatcher foresaw a Bosnian- style catastrophe engulfing Europe if the Major-Delors federal plan, hatched in Maastricht, was forced on the member states.
'We don't want to create the Yugoslavia of the next century . . . We have never been occupied for 1,000 years - or bossed around.'
Mr Major could not agree. 'I am not in favour of referendums,' he later told MPs.