A senior Labour peer has stepped down from the party, blaming Jeremy Corbyn's "lukewarm" attempts to tackle anti-Semitism.
Lord Parry Mitchell said Labour was a "lost cause" in a ferocious attack on the leader following Corbyn's triumphant victory in the leadership battle against Owen Smith.
He also claimed pressure group Momentum had the Labour party "by the throat".
"Jeremy has no leadership qualities whatsoever – his little group like him and they think he's the Messiah, but he will never become the leader and prime minister of this country," Lord Mitchell told BBC One's Sunday Politics.
"I'm Jewish and I'm very strongly Jewish, and I make no bones about it, and there's no doubt in my mind that Jeremy himself is very lukewarm on this subject, he's never been as vociferous in condemning anti-Semitism as he should be, and when he does make a mention of it, he combines it with other forms of racism, so he will never say specifically as far as anti-Semitism is concerned.
"But even more than that, he surrounds himself with a coterie of people who hold violent, violent anti-Israel views, and allied with it, they are very hostile to Jews so, in my view, they're pretty bad guys."
However, Jeremy Corbyn vehemently denied claims that his approach to tackling anti-Semitism in the party was lacking.
"I think it's unfortunate that he would say that because it's not a fair comment and I would hope that he would reflect on that," he told The Andrew Marr Show on Sunday (25 September). "Clearly there are diverse views in the party on the Middle East but there is absolute unity on opposing anti-Semitism and any form of racism, that is very clear."
Lord Mitchell's accusations are the latest in an ongoing anti-Semitism row following Baroness Chakrabarti's inquiry, who was controversially made a Labour peer within weeks of her report.
She concluded the party was "not overrun by anti-Semitism, Islamophobia or other forms of racism" however, recommended new sanctions for any members engaging in divisive practices.
In a letter to The Times in August, Lord Mitchell called Baroness Chakrabarti's report an "insipid whitewash".