Parry Mitchell, a Jewish member of the House of Lords and a former frontbencher under Ed Miliband, said anti-Semitism in Labour had been "permitted to fester" under Mr Corbyn.

In a letter to The Times this morning, Lord Mitchell said the inquiry led by Shami Chakrabarti, which concluded the party was not "over-run" by anti-Semitism, was an "insipid whitewash".

He said he will resign if Corbyn is re-elected leader.