Boris Johnson has urged Britons to drop their cultural "lust" to buy mansions in the Home Counties or those with "colossal grouse moors" and instead give to charity.
Speaking to the Huffington Post UK, Johnson said the "trouble with people in this country" was they wanted to use any money they amass to buy "the biggest possible house they can" which they hope to pass onto the next generation, rather than giving to charitable causes.
"I think it's a cultural thing. The trouble with people in this country is what they want to do is when they've amassed colossal wealth is buy the biggest possible house they can with the most colossal grouse moor they can find and then try and in some desperate way perpetuate it and pass it onto their children for some unknown reason," the London Mayor said.
Johnson attacked the "absolutely ridiculous" British attitude of regarding rich philanthrophists as "somehow ostentatious". "That is the tragedy," he said.
The London Mayor held up American attitudes towards wealthy people giving to charity, calling for a "more simple system of giving in the tax code".
"There is still something in Britain that regards giving in Britain on a huge scale as somehow ostentatious. That is ridiculous, that is absolutely ridiculous. Te sooner people get over their lust to buy great schlosses in the home counties or indeed the grouse moors and give to great causes in London, the better."
Johnson, who owns a £2.3 million house in Islington and a Henley home, was speaking at a City Hall press conference to mark the launch of New York Mayor Michael Bloomberg's "Mayors Challenge In Europe", which will award five million euros (£4.2 million) for the "boldest" idea produced in Europe which could improve city life.
Speaking alongside Johnson, New York Mayor Michael Bloomberg quipped: "I'm reasonably successful but I've never wanted to buy a grouse moor."
Bloomberg also said that he had 98 days left as Mayor for the city, adding: "then I'm looking for a job".
The Mayors were joined by the Mayor of Warsaw, Hanna Gronkiewicz-Waltz, and Florence Mayor Matteo Renzi.