It was the moment when the Iron Lady showed she was a mighty wielder of the handbag, establishing her reputation as an uncompromising prime minister.
In the summer of 1984, the grocer's daughter from Grantham marched into the former French royal palace at Fontainebleau to demand, as she had put it earlier, "our money back" from the European Commmunity.
Thatcher fans regard the European Council of June 1984 as one of their heroine's finest hours when she forced the French and Germans to reverse an unfair budget deal to establish the multi-billion pound "British rebate".
But on the 25th anniversary of one of Thatcher's proudest moments, the French have decided to put a rather different gloss on the events at Fontainebleau.
Francois Mitterrand, the late French president who once famously said that Thatcher had the "eyes of Caligula and the lips of Marilyn Monroe", believed his adversary had suffered a humiliating defeat which saw her cry in private.
The thoughts of Mitterrand, who died in 1996, are revealed by his close aide Jacques Attali in a special BBC programme to mark the 25th anniversary of the summit which established what France scornfully calls the "cheque Britannique".
Attali tells today's edition of the Record Europe on BBC Parliament that Thatcher only secured a modest increase in its rebate. Under the terms of its entry to the EEC in 1973, Britain received back from Brussels £1 for every £2 it paid over, a far less generous deal than that enjoyed by France. At Fontainebleau Thatcher won a rebate of 66% of the gap between what it paid in and what was paid back.
"It was a defeat because she was coming there to get twice as much as she has got," Attali says of Thatcher who had aimed, he claimed, for a 100% cashback.
And then, showing that Thatcher is still regarded with disdain among the bien pensants of the European elite, Attali turns personal. "Actually she cried. Mitterrand told me: 'She's broken like a piece of glass'. And she actually was. I was surprised to see that, she was really broken when she accepted the final deal."
Attali's criticism of Thatcher will upset her fans, though they will no doubt say he is in no position to speak out on finance. He ran into trouble in the early 1990s when it turned out that the European Bank for Reconstruction and Development, of which he was the first president, had kitted out its London office in a style befitting the former royal residents of Fontainebleau.
Back in Britain, Attali is dismissed for speaking what Thatcher's redoutable former press secretary, Sir Bernard Ingham, would describe as "bunkum and balderdash". Sir Michael Butler, Britain's EC ambassador at the time, said Thatcher did well to secure a 66% rebate from the French who had only wanted to give 50%.
Lord Owen, the former foreign secretary who was then leader of the SDP, tells the programme: "There are times when diplomacy requires a tough stance and the rebate negotiations were certainly one of them. They were trying to roll her over, they were trying to roll her over actually with a lot of male chauvinism and she stood her ground. And good luck to her."