Jeremy Corbyn’s new general election campaign guru once warned Israel that the country was “digging its own grave” by taking action in Gaza.

Andrew Murray, 59. a long-time Communist Party member and current head of staff at Unite, the country’s biggest trade union, spoke out against Israel’s “bloody aggression” in a Stop the War speech in 2012.

At the event, in which the former Stop the War chair cheered the “props of Israeli power crumbling,” he decried Israeli action in Gaza as “crude and barbaric violence”.

He said he stood in “solidarity with the heroic Palestinian people in Gaza,” and that “Palestine stands undefeated and unbowed despite the bloody aggression by one of the greatest military powers on earth”.

Jeremy Corbyn

Jeremy Corbyn

He added: “We have a message for the Israeli embassy, the Israeli government… every time you kill a Palestinian child you are digging your own graves.”

Murray, a former Morning Star journalist who quit the Communist Party in December in order to join the Labour Party, has now been seconded to Labour “to support, not head up, the campaign”.

He has drawn angry reactions for calling on Labour to boycott union peers in Israel, urging colleagues to “drop the illusion that the Histradut [Israel’s trade union movement] is a proper trade union and break the links”.

Murray is described as one of Labour leader Jeremy Corbyn’s oldest friends and has reportedly been brought in to oversee links between the party and the leader’s office.