The 47-year-old, who has recently become a high-profile political activist in Israel, opposing Benjamin Netanyahu’s rightwing populist coalition and its plan to weaken judicial oversight, told the Guardian he intervened after speaking with peace activists in his home country who were “completely devastated” and “feeling abandoned and betrayed by supposed allies” in peace efforts, after academics, artists and intellectuals signed letters which failed to condemn Hamas.

Harari’s aunt and uncle lived in one of the kibbutzim targeted by Hamas in attacks that killed more than 1,400 people and saw more than 220 people taken hostage. They had survived after hiding while gunmen went house-to-house killing neighbours.

Speaking about the reaction from parts of the left in the US and Europe while on a visit to London, Harari said it was “shocking to hear some of the responses that did not only not condemn Hamas, but placed all responsibility on Israel” and to see “the lack of solidarity with regard to the horrific attacks on Israeli civilians”.

The letter, whose other signatories included the celebrated Israeli novelist David Grossman, said: “We never imagined that individuals on the left, advocates of equality, freedom, justice, and welfare, would reveal such extreme moral insensitivity and political recklessness.”