AceShowbiz - The stars of the "Harry Potter" franchise have criticized London mayor Boris Johnson after the politician complained a new wizarding theme park should have been built in Britain, not America. Johnson recently blasted bosses at film giant Warner Bros., calling them "utterly mad" for allowing a Harry Potter park to be created in Florida, when the books and movies are all set in the U.K.

The franchise's stars, including Michael Gambon and Tom Felton, disagree with Johnson and have now waded into the debate, insisting a similar attraction would not work in London. Speaking at the launch of The Wizarding World of Harry Potter in Orlando, Florida on Wednesday night, June 16, Gambon tells Britain's GMTV, "Oh he's a silly old fart isn't he, really? Boris Johnson... What's he talking about? I mean only 10 people live in England don't they? You've got to have it in America to get the money back."

Felton has also laughed off Johnson's comments, insisting the weather isn't good enough in England to host the outside park: "I've got a few words for Boris... well mate, if you want the park to be open for 30 days a year then put it in England, but come on, realistically this is the place to do it."

Daniel Radcliffe has also spoken out about the issue, insisting that if Johnson wants to build a Harry Potter theme park in the U.K., then he should use his political influence to push the decision through: "Of course it would be absolutely wonderful to have an equivalent in London and I'm sure Boris, as the mayor of London, is surely the man with the power to make that happen, one would assume."

While Rupert Grint adds, "We should have one, it's just amazing."