'No,' she replied. 'For three reasons. Firstly I don't dance with drunks. Secondly, they are playing the Peruvian national anthem and you should be standing to attention. And thirdly, I am the cardinal archbishop of Lima.'
Peter Paterson has, sadly, been unable to prove the veracity of this story, suspecting it to have been cooked up by one of the curmudgeonly old Foreign Office types Brown made it his business to antagonise. But there are more than enough other anecdotes about Brown's colourful career in Tired and Emotional to make up for it.
Of all the people to occupy the great offices of state in the last 50 years, none has done more to amuse the British people, apart, perhaps, from Winston Churchill. This is an Olympian comparison from which to assess Brown's career, but it does make you wonder what on earth he thought he was doing with his life.
Apart from what new light they can throw on recent history, political biographies ought to tell us what drove the individual to endure the banalities - the cold sausage rolls, endless repetitions of the same dull speeches to the converted, the intrigue and infighting - which constitute the life of the ambitious MP. If Peter Paterson's engagingly written book has a failing it is that by the end you are left wondering why Brown bothered. Perhaps it was just because power, like Everest, was there.
Hartley Shawcross, who coined the hubristic aphorism 'we are the masters now,' believes that Brown was destroyed by drink and a bad marriage. Of his legendary drunkenness, there were stories galore, even if the newspapers and television failed to report them. But reading Paterson's account of his treatment of his long-suffering wife, Sophie, which culminated in his walking out of the family home, whistling, on Christmas Eve, one gets the strong impression that the only words appropriate to him are 'total shit'.
Biographers often remark that in order to spend two or three years of your life in the company of someone, you really must like them. It is said that even at the end of his researches, Peter Paterson still entertained an affection for George Brown. This is hard to understand, because the figure who emerges appears endowed of a driving ambition, but almost devoid of a conscience.
Of his reasons for joining the Labour Party in the first place we are left largely ignorant. His rise to prominence is portrayed as the triumph of chippiness, naked will and a viperous tongue over weaker mortals. And his only lasting memorial is the fact that the Tower of London is open to tourists on Sundays.
We know that he had the above qualities in abundance, yet he also built a solid powerbase in the party. He could not have risen to the deputy leadership without other attributes, including a personal popularity. And for all that the public tut-tutted about his notorious boozing, they loved him for the fact that he was a card.
Paterson believes that Brown belonged to the Labour Party of Keir Hardie and Ramsay MacDonald, before he succumbed to the embrace of the Establishment. The point makes sense, as far as it goes: by the time Brown achieved prominence, the party was dominated by people he dismissed as 'intellectuals' and run by Harold Wilson, a man who recognised opportunities the way a snake's belly recognises the easiest rise in the ground.
It is salutary to be reminded that for all the waves he made, Brown spent less time in cabinet than he did selling fur coats as a young man. Paterson claims Resolution 242 as a lasting memorial to his time at the Foreign Office, but it is hard to see why yet another ignored resolution, however masterly in its ambiguity, should really be taken that seriously. His Department of Economic Affairs was buried by the Treasury (although not before Brown had managed to leave the top secret National Plan in the back of a Mini). And the Labour Party is now entirely in the hands of people he would have affected to despise.
It is as a sort of oratorical armoured car that he is best remembered. He belonged to an age when politicians still fought elections out on the stump rather than from behind a cake of make-up in a television studio. When it came to dealing with hecklers, said one awestruck reporter: 'He had the timing of Bob Hope and the wit of Ken Dodd.'
When a young female heckler interrupted him with the cry 'never' in one speech, he stopped, looked her in the eye and said politely: 'My dear girl, there are some big words which little girls should not use, and 'never' is one of them.' The put-down - devastating, sexist and patronising - captures the man perfectly.
Familiar though we are, through the Crossman, Benn and Castle diaries, of much of the infighting which racked the Labour governments of the Sixties and Seventies, the sheer poison infecting the relationship between Brown and Harold Wilson still takes some comprehending. The wonder is that they survived as cabinet colleagues as long as they did.
Peter Paterson's book will doubtless be criticised by hagiographers and historians for failing adequately to explore the political tensions within the party that the Brown / Wilson tension exemplified. This may indeed be a failing, but of all the recent political biographics, this assuredly is the most entertaining read.