A union leader was being “lazy, ignorant and offensive” in likening a Labour MP to Hitler, Jewish representatives have said.

Tosh McDonald, the president of train drivers’ union ASLEF, compared support for military action against ISIS in Syria from Hilary Benn MP to Hitler and Mussolini’s support for military action against republicans in Spain in the 1930s.

McDonald, who is a fan of embattled Labour leader Jeremy Corbyn, made the comments at a fringe meeting of the annual Trades Union Congress, but it spawned an angry reaction from Jewish leaders.

Board of Deputies’ vice-president Marie van der Zyl said: “Hitler comparisons like this are lazy, ignorant and offensive. But then, what can one expect from someone who says that Daesh (ISIS) – a totalitarian theocracy that crucifies Christians and sells women as sex slaves – is remotely comparable to the anti-fascists in the Spanish Civil War?”

She added: “It is time for Mr McDonald to engage with reality, and for people in public life to stop misusing Hitler references.”