Jewish Leadership Council chairman Mick Davis, strongly defended Israel's campaign in an article in the Sunday Times.
He wrote that every "right-thinking person" should side with Israel in its conflict with Hamas.
"I side with Israel every morning because I believe in the fundamental right of Israel to exist, in the right of its citizens to security and in the essential duty of its democratically elected government to ensure that security," he wrote. "Three simple beliefs which, if we replace the name of Israel with that of any western democracy, would not be controversial."
While he felt compassion for the innocents in Gaza who had lost their lives, he said he could not use numbers "to judge what is right and wrong". Behind them lay a disparity between how Israel protects its people and how Hamas uses its people as human shields.
Another communal leader, Liberal Judaism chief executive Rabbi Danny Rich, told its members in a letter that he had been silent on the situation until now because he felt "conflicted".