Yesterday, it was eccentricity which was given a voice as a mixed crowd of media and the public listened in increasing disbelief as Heather Mills called for the nation to switch from drinking cows' milk to that of rats and dogs.
The former model, who has hit the headlines with a series of tirades against her estranged husband, Sir Paul McCartney, made the comments as part of animal-rights group Viva's push to persuade people to abandon meat and dairy products, and go vegan instead.
Ms Mills, 39, unveiled the group's two new posters, in which she features, to draw a connection between the rise in global warming and dairy livestock production.
Addressing her audience - dozens of journalists and a handful of bemused tourists - she said: "There are fields of grain just miles from starving children in Africa, being shipped to Europe to feed our livestock.
"There are 25 alternative milks available in health shops and supermarkets.
"Why do we not drink rats' milk, cats' milk or dogs' milk?"
Mills posed in front of a giant mobile billboard bearing the posters, which featured her in a sultry pose and a low-cut sequined vest beside the slogan: "Hey Meaty, you're making me so hot!"
On the other side, the disabled model was pictured in an ad accusing environmentalists of hypocrisy, next to the line: "You haven't got a leg to stand on!"
Mills is not the only person to have toyed with the idea of humans drinking rats' milk. An episode of The Simpsons revolved around Homer rumbling a gangland scheme to supply Springfield Elementary School with milk from farmed rats.
However, for Homer the idea that his children should be brought up on the milk of rattus norvegicus was one not to be encouraged.
Mills said Viva had alerted her to the extent of the effect of deforestation and livestock on global warming. She said that dairy production had a huge effect by producing greenhouse gases.
Mills said: "When [Viva] told me it was 18 per cent - that's more than all global transport - I was in shock. Aeroplanes only bring 3 per cent, while they are being picked on with taxes."
And she called on people to "cut down on one or two meat and dairy and fish dishes a week", adding: "I'm not saying people need to go vegan overnight."
Mills said she was inspired to turn vegan when she met an African woman at the Live 8 event who asked her: "Why don't people stop drinking cows' milk lattes?"
Richard Tester, professor of carbohydrate chemistry and food scientist at Glasgow Caledonian University, said: "It's all to do with viability of collection. Some cultures use horses' or buffalo milk, but the cow has been bred to produce vast amounts of it, enough for humans and their calves, and it's very nutritious.
"Also, you have to take into account the food pyramid. Down through history, it has not been common practice for man to drink the milk of carnivores - it's all part of the food chain.
"For Heather Mills to suggest that rats or dogs could be a suitable replacement is just ridiculous. They just don't lactate the same volumes."
However, Mills's environmental message did not extend to her mode of transport. Rather than the hybrid cars favoured by eco-conscious celebrities, she arrived in a Mercedes 4x4 and conducted a series of interviews inside while the engine was running.