According to a report in this morning's Times, the British Museum has "intimated that the Elgin Marbles could be lent to Athens". The Greek authorities told the Times that the move was significant as it was "the first time they’ve ever said they’d let them out of the museum. We’ve said we’re not disputing the ownership."
Now, whilst Greece may say they're not disputing ownership that is, rather obviously I think, just diplomatic speak. Deep down of course the ownership dispute remains. So, is it really beyond imagination that if the British Museum lends them to Athens that when the loan period runs out they refuse to give them back? It's not like we'll invade them to get them.