A diplomatic row has broken out between the British and Greek governments over the Parthenon Sculptures, also known as the Elgin Marbles.
The Greek Prime Minister Kyriakos Mitsotakis was due to meet Rishi Sunak in London, but No 10 cancelled the meeting at the last minute.
He told reporters he was “deeply disappointed by the abrupt cancellation” of the meeting.
Mr Mitsotakis rejected an alternative meeting with the deputy prime minister.
The cancellation came a day after Mr Mitsotakis told the BBC’s Laura Kuenssberg that the marbles should be returned, as having some of the artefacts in London and the rest in Athens was like cutting the Mona Lisa in half.
The Greek prime minister told reporters on Monday evening he was disappointed the meeting had been cancelled “mere hours before its slated time”, saying: “Those who firmly believe in the correctness and justice of their positions are never hesitant to engage in constructive argumentation and debate.”
Mr Mitsotakis said: “Greece and Britain share longstanding ties of friendship, and the scope of our bilateral relations is extensive.
“Our positions on the matter of the Parthenon Sculptures are well-known. I had anticipated engaging in a discussion with my British counterpart on this issue, as well as addressing significant global challenges such as the situations in Gaza and Ukraine, the climate crisis, and migration.”
Sources with knowledge of the mood in the Greek government said Mr Mitsotakis was “baffled” and “annoyed”.
The meeting had been due to happen at lunchtime on Tuesday and, the BBC understands, was due to last 45 minutes.
But Mr Mitsotakis’s appearance on the BBC’s Sunday with Laura Kuenssberg programme had irritated Mr Sunak.
The British government confirmed the cancellation and offered the Greek PM a meeting with Deputy Prime Minister Oliver Dowden instead.
A senior Conservative source said: “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.”