Brian Paddick, the Liberal Democrats' London mayoral election candidate, said this week that his Labour opponent had used "dog- whistle tactics to play divide and rule" and declared: "Labour should be ashamed to have him as a candidate".

Mr Paddick said: "Ken Livingstone knows exactly what he's doing when he conflates being Jewish with being rich and makes other deliberately provocative and offensive remarks about Jewish people.

"We should have learnt from history that when the economic situation is difficult, extremists come out to play. For Ken to say such things at this time is troubling, dangerous, and completely irresponsible.

"As far as the Jewish community goes, he's had it. They needed convincing after last time, but he has convinced them in completely the opposite direction."

Until his retirement as deputy assistant commissioner of the Metropolitan Police in 2007, Mr Paddick was Britain's most senior openly gay police officer. He said that minority experience had heightened his understanding of the Jewish community.

"The gay and Jewish communities have some common heritage of being scapegoats and being picked on. I've always felt comfortable among the Jewish community. I have an affinity with Jews and know what it's like to be completely wrongly discriminated against simply because you come from a particular background or community."

Mr Paddick appeared at last December's Limmud conference to discuss the upcoming election. It was, he said, a valuable experience.

"There was only one mayoral candidate at Limmud - me. The others did not think it was important enough to go. I did feel that there was an understanding that I 'got it'. That's what came across from the people in the room."

Mr Paddick will speak at a breakfast meeting organised by the London Jewish Forum on April 22.