A conservative campaign group has urged Trinity College to take legal action following the vandalism of a portrait of Lord Balfour last year, after police investigations closed without arrests.

The portrait of the former British Prime Minister, who in 1917 authored the Balfour Declaration supporting the establishment of a Jewish state, was spray-painted red and slashed with a knife during a protest in March 2024.

Palestine Action, a group proscribed under UK terrorism legislation earlier this month, publicly claimed responsibility for the incident.

In March this year, Cambridgeshire Constabulary concluded its investigation without identifying or charging any suspects. In response, the Great British PAC, a right-wing campaign group, published an open letter urging Trinity College to pursue further action.

In a post on X, the group stated: “We’re calling out the failure to prosecute the vandalism of Lord Balfour’s portrait at Cambridge. When Palestine Action admits guilt and nothing is done, justice is not being served.”

The open letter, addressed to Trinity’s Master, Dame Sally Davies, was signed by Jacob Watts, a Cambridge undergraduate and Deputy Universities Director of the organisation, and Jake Reed, the group’s Universities Director. It expressed “grave concern” over the closure of the police investigation.

“As a University of Cambridge student myself, I am deeply committed to ensuring that criminal acts damaging our institution’s heritage do not go unpunished,” wrote Watts. The group also indicated it was “actively exploring a private prosecution” and requested Trinity’s assistance in providing evidence.

The Great British PAC, chaired by former Reform UK Deputy Leader Ben Habib, has been described by charity Hope Not Hate as a “far-right pressure group packed with extremists”.

In response to this, the group stated they are “patriots, not partisans,” who come “from across the political spectrum,” and that “Hope not Hate’s smear campaign” is “part of their tired old playbook” to “delegitimise those who disagree”.

When the painting by Philip Alexius de László from 1914 was damaged, Palestine Action justified their actions on Instagram by claiming that the Balfour Declaration “began the ethnic cleansing of Palestine by promising the land away – which the British never had the right to do.”

Following the incident, Trinity College issued a statement regretting “the damage caused to a portrait of Arthur James Balfour during public opening hours,” confirming that police had been informed.

A spokesperson for Trinity has now said: “Trinity College continues to condemn this act of vandalism in the strongest terms. Since the attack on the portrait of Lord Balfour, the College has worked closely with the Police and supported their investigation in every way possible.

“Trinity College will continue to cooperate with the Police in the event further evidence becomes available so that the perpetrators can be brought to justice. The portrait of Lord Balfour by Philip Alexius de László is undergoing restoration,” the College continued.