The Louvre feels that Greece is putting pressure on them to call for the British Museum to return the Elgin Marbles. From the information given in the article though, it is unclear what evidence there is to support this particular claim.
Daily Telegraph 
Greeks enlist Louvre in battle for Elgin Marbles
By Henry Samuel in Paris
Last Updated: 1:51am GMT 21/03/2007
Greece is putting pressure on the Louvre museum in its long-running campaign to retrieve the Elgin marbles from Britain.
The Greeks have refused to lend the French an ancient sculpture for an exhibition because, they say, it is too fragile to be moved from Athens.
But Louvre sources believe the bronze artwork is being used as a bargaining chip to pressure the museum into joining Greek calls for the Elgin marbles – taken from Greece in the nineteenth century and now in the British Museum – to be returned to Athens.
The Louvre opened its first exhibition dedicated to ancient Greek sculpture yesterday without Praxitelis’ sculpture The Ephebe of Marathon.
Paris and Athens have been engaged in a slanging match since the Greek culture ministry declared last month that it would not lend the artefact, because it was on a list of works that could not be moved.
The Louvre said it was “stupefied” at the “more than belated” decision not to give clearance to the sculpture’s inclusion because, it said, the green light was given two years ago. Greek authorities deny this.
The row has underlined the debate over who has claim over ancient Greek art – Greece or the entire Western world, as recently suggested by Unesco.