Rishi Sunak has denied throwing a “hissy fit” by scrapping a planned meeting with his Greek counterpart after accusing him of grandstanding about the return of the Parthenon Sculptures to Athens.

The Prime Minister sparked a diplomatic row by controversially snubbing Kyriakos Mitsotakis after the Greek leader compared the artifacts’ removal to cutting the Mona Lisa in half.

George Osborne, the former chancellor-turned British Museum chairman, said Mr Sunak may have been indulging in a “hissy fit” as he insisted the feud would not stop long-running talks on an exchange deal to allow the Elgin Marbles to be displayed in Greece.

Asked whether the former senior Tory was right, Mr Sunak told journalists travelling with him to Dubai for the Cop28 climate talks: “No, no. I think I’ve said everything I’ve got to say on this in Parliament the other day and now I’m focused on delivering for people on the things they care about.”

The Prime Minister also hinted that a loan arrangement could be impossible due to Greece’s stance.

“Our position is very clear – as a matter of law the marbles can’t be returned and we’ve been unequivocal about that,” he said.

“And I think the British Museum’s website itself says that in order for the loans to happen the recipient needs to acknowledge the lawful ownership of the country that’s lending the things and I think the Greeks have not suggested that they are in any way shape or form willing to do that.

“Our view and our position on that is crystal clear: the marbles were acquired legally at the time.”

Mr Osborne, chairman of the London museum where the friezes are on display, said he was pressing on with negotiations on the marbles even though it was clear from events this week that Mr Sunak’s administration would not support an exchange.

But he said the stance taken by Opposition leader Sir Keir Starmer – who met Mr Mitsotakis in London this week – could pave the way for it to happen under a future Labour government.

Cop28 summit
Prime Minister Rishi Sunak speaks to journalists on the plane to Dubai for the Cop28 summit (Stefan Rousseau/PA)

Mr Sunak brushed off suggestions the Labour leader’s meeting with the Greek premier could make him appear more statesmanlike, pointing to his own “fantastic track record” of global diplomacy over the last year.

“I feel pretty good about how we’ve conducted our foreign policy and engaged all our partners and allies around the world over the past year and delivered real benefits for the British people at home in investment and jobs and better security,” Mr Sunak told reporters.

A spokesman for Sir Keir has said his potential premiership would “not spend any time legislating on this matter” but that it “wouldn’t stand in the way” of a mutually beneficial agreement between the museum and Athens.

The 1963 British Museum Act prohibits the removal of objects from the institution’s collection, a position in law that Mr Osborne said would ensure Greece would have to return the sculptures following any exchange.

Greece has long demanded the return of the historic works, which were removed by Lord Elgin from occupied Athens in the early 19th century when he was the British ambassador to the Ottoman Empire.

Part of friezes that adorned the 2,500-year-old Parthenon temple on the Acropolis, the Elgin Marbles have been displayed at the British Museum in London for more than 200 years.

The remainder of the friezes are in a purpose-built museum in Athens.

In comments made on his podcast Political Currency, Mr Osborne reiterated that he has “been exploring with the Greek government on behalf of the museum” an arrangement that would allow the sculptures to be displayed in Greece.