Boris Johnson says he supports plans to redevelop parts of the Southbank Centre - but the skaters must remain in the current undercroft.
Speaking at a planning meeting at City Hall, Mr Johnson said:
"The skate park is the epicentre of UK skateboarding and is part of the cultural fabric of London. This much-loved community space has been used by thousands of young people over the years.
"It attracts tourists from across the world and undoubtedly adds to the vibrancy of the area - it helps to make London the great city it is."
More top news
On the first Stephen Lawrence Day, Dr Neville Lawrence says he instead focuses on stopping further deaths
Matt Everard, from Essex, who described the purchase as the result of a ‘boozy night’, hopes the vehicle will reach 90mph.
The protesters are set on defying police orders and marching to Parliament.