A portrait of Lord Balfour, the former prime minister, at the University of Cambridge has been damaged by pro-Palestine protesters.

In a video posted on social media by Palestine Action, a member of the group is seen spray-painting and slashing the portrait inside Trinity College.

A woman can be seen defacing the work with red paint, before slicing the canvas with a sharp object.

Balfour, was one of the chief supporters of creating a Jewish homeland in Palestine, cemented by the Balfour Declaration of 1917 that gave British backing to the movement.

A nephew of Lord Salisbury, he succeeded his uncle as prime minister in 1902 and subsequently became foreign secretary.

The Instagram video was accompanied the caption: “Palestine Action spray and slash a historic painting of ‘Lord’ Balfour in Trinity College, University of Cambridge.

“Written in 1917, Balfour’s declaration began the ethnic cleansing of Palestine by promising the land away – which the British never had the right to do.

“After the Declaration, until 1948, the British burnt down indigenous villages to prepare the way; with this came arbitrary killings, arrests, torture and sexual violence including rape.

“The British paved the way for the Nakba and trained the Zionist militia to ethnically cleansed over 750,000 Palestinians, destroy over 500 villages and massacre many families.

“The Nakba never stopped and the genocide today is rooted and supported by British complicity.

“Now, Elbit Systems, Israel’s biggest weapons manufacturer use Britain as a manufacturing outpost to build arms which are ‘battle-tested’ on Palestinians.”

The University of Cambridge and Palestine Action were contacted for comment.