Pro-Palestinian campaigners have threatened to picket the Edinburgh International Film Festival in June unless it hands back sponsorship money from Israeli sources.

A letter from the Scottish Palestine Solidarity Campaign accuses the festival directors of accepting money from the Israeli Embassy “while people in Gaza are still living in the rubble of their homes, and Gaza victims of Israel’s white phosphorous attacks are still in critical care.”

It calls on supporters to lobby the festival directors to refuse “Israel’s tainted money”.

A spokesman for the film festival said that many cultural institutions gave funds to help filmmakers show their work internationally.

“We do not make these arrangements based on any allegiance or otherwise with the political regime in any given country.

“Choosing not to accept support from one particular country would set a dangerous precedent by politicising what is a wholly cultural and artistic mission,” said the spokesman.

Only one Israeli film is due to be shown at the festival, Tali Shalom Ezer’s Surrogate which examines the relationship between a troubled young man and his sex therapist. The festival’s website calls it “concise, brave and original”.

Also due to be shown is Nakba, a Belgian film by Max Francos, described as “a powerful and visually stunning political documentary which unfolds entirely through images and music. Nakba tells the story of the Palestinian exodus and the 1948 Arab Israeli war.”