A pro-Palestinian activist has slashed and sprayed paint on a picture of the British politician who cleared the way for the foundation of modern Israel.

Footage shared on X showed a woman defacing the 1914 painting of Lord Arthur Balfour at Trinity College at the University of Cambridge on Friday.

Lord Balfour was behind the Balfour Declaration – a 1917 document which pledged the formation of a “national home for the Jewish people” in Palestine.

The post by activist group Palestine Action said: “Balfour’s declaration began the ethnic cleansing of Palestine by promising the land away — which the British never had the right to do.”

The defacing was intended to symbolise the bloodshed of the Palestinian people since the Balfour Declaration was issued in 1917, the group said.

A Trinity College spokesman said: “Trinity College regrets the damage caused to a portrait of Arthur James Balfour during public opening hours.

“The police have been informed. Support is available for any member of the College community affected.”

Cambridgeshire Constabulary said it received an online report of criminal damage to the painting on Friday.

Officers were at the scene to secure evidence and progress the investigation, but no arrests have been made.

Palestine Action describes itself as “a direct-action network of groups and individuals” aiming to act against “the sites of Elbit Systems and other companies complicit in Israeli apartheid”.

The incident comes after a report by the United Nations human rights office said the establishment and expansion of Israeli settlements in the West Bank and east Jerusalem amounted to a war crime.

Foreign secretary Lord Cameron said on Friday the UK would join the US and other allies to create a maritime corridor to deliver aid directly to Gaza.

The UK Government has also called for a “humanitarian pause” in the fighting to enable aid to get into Gaza and hostages held by Hamas to be released.