(Bloomberg) -- Prime Minister Rishi Sunak canceled — at the last minute — a one-on-one meeting with his Greek counterpart in London, triggering a diplomatic spat and dragging out a centuries-long feud that had appeared close to resolution.

“I express my annoyance for the fact that the British prime minister canceled our scheduled meeting just hours before it was due to take place,” Greek Prime Minister Kyriakos Mitsotakis said in a statement late Monday. Their meeting had been set for Tuesday.

It became impossible for the meeting to go ahead due to Mitsotakis’s commentary regarding the Parthenon marbles, one senior Conservative Party official said, asking not to be named to discuss private matters.

“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?,” Mitsotakis said on the BBC on Sunday, referring to the sculptures’ removal from the acropolis in Athens, where others like them still stand.

The historical artifacts are housed in London’s British Museum and both countries claim them as their own. In recent years, the sides had been close to resolving the dispute by brokering an arrangement whereby they could be seen in Athens, from where they were taken by British diplomat Lord Elgin in the early 19th century.

Read more: Greek PM to Raise Elgin Marbles With Sunak, Starmer in UK

Mitsotakis insisted in his statement that what he told the press didn’t contain anything that deviated from his previous stance. 

“Greece’s positions on the issue of the Parthenon Sculptures are well known,” he said. “I was hoping to have the opportunity to discuss them with my British counterpart as well, along with the major challenges of the international situation: Gaza, Ukraine, Climate crisis, migration.” 

The Greeks received a call at around 6 p.m. UK time just as Mitsotakis’ meeting with UK opposition-party leader Keir Starmer was ending, said one person familiar with how the cancellation played out. Mitsotakis was offered a meeting with Britain’s Deputy Prime Minister Oliver Dowden instead, but he “hasn’t chosen to take that up,” Cabinet minister Mark Harper told the BBC on Tuesday morning.

The Financial Times earlier reported Starmer was privately not prepared to change UK law concerning the sculptures but wouldn’t stand in the way of a loan deal if the British Museum and the Greek government could agree one.

Sunak’s Conservatives trail Labour by about 20 points in national polls ahead of a general election expected next year. Starmer and Mitsotakis discussed the marbles during their meeting and both sides presented their arguments, a person familiar with the matter told Bloomberg.

The Greek premier’s comments were no different than what he’s said in the past and reflect the country’s fixed positions on the issue, a senior Greek official said, adding that in any case the matter doesn’t concern the British government but the British Museum.

Josh Lambkin from the Parthenon Project, which is working with the British Museum and Acropolis Museum to try to broker a deal, criticized Sunak’s decision.

“It’s a shame the British prime minister feels he can’t discuss the subject of the Elgin Marbles with the Greek prime minister, especially given how much both countries stand to gain from a sensible resolution on this matter,” he said.

The cancellation also risks a relationship that might have helped Sunak improve cooperation among European nations coping with a surge of asylum seekers. 

“If the Prime Minister isn’t able to meet with a European ally with whom Britain has important economic ties, this is further proof he isn’t able to provide the serious economic leadership our country requires,” a Labour Party spokesperson said. 

--With assistance from Alex Wickham.

(Updates with Harper comment in eighth paragraph.)

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