Boris Johnson has taken umbrage with George Clooney's suggestion that the 2,500-year-old Elgin marbles should be returned to Athens. It's a perfectly reasonable comment to make, given the sculptures were removed from the Parthenon 200 years ago and now reside in the British Museum.

George Clooney The Monuments MenGeorge Clooney in 'The Monuments Men'

Clooney made the remarks during the UK promotion of his new movie The Monuments Men, which focuses on the rescuing of classic artworks stolen by the Nazis during World War II. At a press conference in London, the award-winning filmmaker said returning the marbles to Athens is "probably the right to do" and he was supported by actors Matt Damon and Bill Murray.

The marbles were removed from the Parthenon by Lord Elgin, who later sold them to the British government for $35,000. 

According to the Evening Standard, London Mayor Boris Johnson rejected Clooney's suggestion in typical.Boris style, saying, "Someone urgently needs to restore George Clooney's marbles. Here he is plugging a film about looted Nazi art without realising that Göring himself had plans to plunder the British Museum.

 "And where were the Nazis going to send the Elgin marbles? To Athens! This Clooney is advocating nothing less than the Hitlerian agenda for London's cultural treasures. He should stuff the Hollywood script and stick to history."

John Goodman George ClooneyJohn Goodman [R] and George Clooney [L] in 'The Monuments Men'

Clooney - who co-wrote, directed and stars in The Monuments Men, out in the UK this week - said the issue was first raised by a Greek journalist in Berlin on Saturday.

"I do think it's worth having an open discussion. It was one of a hundred questions at a press conference, a Greek reporter asking me about the marbles, and I just said I thought it was probably a good idea if they found a way back at some point," he said.

The Monuments Men premiere went ahead in a blustery Leicester Square last night, with Clooney joined by co-stars John Goodman, Jean Dujardin and Downton Abbey's Hugh Bonneville. See all our pictures from The Monuments Men premiere.

It's no secret the director has run into problems throughout production of the movie and it appears to have fallen short of many critics' expectations.

"Even low expectations won't help you here, with a story that's neither amusing nor dramatic," says James Mottram of The List.

"A frustratingly flat film that drifts from moment to moment with a curious lack of urgency and an overbearing sense of self-importance," said William Goss of Film.com.

"This displays none of the nimble-witted sleight of hand, nor indeed old-fashioned suspense, of Argo, the last historical caper movie with which Clooney was involved," said Andrew Pulver of The Guardian.

The Monuments Men hits theaters in the UK on Friday (February 14, 2014).

Watch the Monuments Men trailer: