The SNP’s Stephen Flynn has joined calls for the Elgin Marbles to be returned to Athens.

The intervention from the party’s Westminster leader comes as a diplomatic row engulfs No 10 following Rishi Sunak’s last-minute snub of the Greek Prime Minister.

Kyriakos Mitsotakis was supposed to meet the Tory leader in Downing Street today, but the UK Government has cancelled, instead offering him a meeting with Deputy Prime Minister Oliver Dowden

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The spat came after Mr Mitsotakis reiterated the Greek government's long-standing call for the British Museum to return the sculptures taken from the Pantheon in the early 19th century. 

“I mean, it’s as if I told you that you would cut the Mona Lisa in half, and you will have half of it at the Louvre and half of it at the British Museum, do you think your viewers would appreciate the beauty of the painting in such a way?” he told the BBC's Laura Kuenssberg on Sunay.

The Herald: Prime minister of Greece Kyriakos Mitsotakis had spoken about his want for the ‘reunification’ of the Elgin Marbles (Jeff Overs/BBC/PA)

The sculptures from the Parthenon and other structures from the Acropolis in Athens were removed by Lord Elgin after he paid around £70,000 to the ruling Ottoman Empire.

The removal was controversial at the time, and the Greeks have long accused the aristocrat of looting the priceless antiquities, which have been a cornerstone of the British Museum’s collection.

On Monday night, one senior Conservative source told the BBC: "It became impossible for this meeting to go ahead following commentary regarding the Elgin marbles prior to it.

"Our position is clear - the Elgin Marbles are part of the permanent collection of the British Museum and belong here. It is reckless for any British politician to suggest that this is subject to negotiation."

Mr Flynn shared the comment on X, the site formerly known as Twitter. “Absolutely agree,” he tweeted. “This shouldn’t be subject to negotiation. The Elgin marbles were stolen and should be returned. Easy.”

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Transport Secretary Mark Harper said it was a “matter of regret” that Mr Mitsotakis had not wanted to meet with Mr Dowden after he was dinghied by Mr Sunak.

“The Deputy Prime Minister offered to meet the Greek prime minister today and it proved not possible to make that happen,” Mr Harper told BBC Breakfast.

“That’s a matter of regret. That offer was made.

“But the Government set out its position about the Elgin Marbles very clearly, which is they should stay as part of the permanent collection of the British Museum.”

Asked whether it was a snub, he told Sky News: “The Prime Minister wasn’t able to meet the Greek prime minister. He was offered a meeting with the Deputy Prime Minister, which proved not to be possible for him to take up. So, I don’t think I’d characterise it the way you have.

“Discussions continue between our governments about important matters.”

The 1963 British Museum Act prohibits the removal of objects from the institution’s collection, however, for the past two years, there have been delicate negotiations between the museum and Greece’s government.

Chairman George Osborne has previously said they are exploring ways for the statutes to be displayed in Greece.

But when asked about such an agreement, Mr Sunak’s spokesman told reporters: “We have no plans to change our approach and certainly we think that the museum is the right place for them.”

In a statement, a spokesman for the Greek prime minister’s office said: “The prime minister is disappointed that Prime Minister Sunak cancelled their bilateral meeting at the 11th hour today.

“Greece and Britain have a very deep history of friendship and cooperation, and the Greek government is extremely surprised by this decision.

“The prime minister was looking forward to discussing a range of topics of mutual interest including the Israel/Gaza conflict, Russia’s illegal invasion of Ukraine, climate change, as well as common challenges such as migration, and of course the Parthenon Sculptures.”

Mr Mitsotakis used a social media post to express “dismay” that the meeting had been cancelled “just hours before it was due to take place”.

According to an online translation, he said: “Anyone who believes in the correctness and justice of their positions is never afraid of opposing arguments.”

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Mr Mitsotakis did manage to meet Labour leader Sir Keir Starmer during his visit to the UK.

Sir Keir had indicated he would tell the Greek premier that a Labour government would not change the law but that he would not stand in the way of a loan deal that was mutually acceptable to the museum and the Greek government.

Labour criticised Mr Sunak’s decision to cancel his meeting with his Greek counterpart.

Shadow policing minister Alex Norris told Sky News: “It seems a bit unnecessary, I think, for our Government to be acting in that way.”