A group of peers have resigned the Labour whip with one claiming leader Jeremy Corbyn and “his circle” are “antisemitic”.
Ex-Labour general secretary Lord Triesman is among those to resign, describing how “the experience of life in the party has become sickening”.
Labour sources confirmed his resignation along with the resignation of Lord Turnberg, a former president of the Royal College of Physicians.
Former health minister Lord Darzi also confirmed to Sky News he has quit. He said: “I am leaving the Labour whip to sit as an independent.
“As an Armenian survivor of the Armenian genocide I have zero tolerance to antisemitism, Islamophobia or any other discrimination against religion or race.”
However, Lord Winston told Sky News he is not planning to follow his former colleagues and resign the Labour whip for now.
He said: “It is desperately hard at the moment to be part of the party, but we have to change it. And I believe it will change.”
Lord Triesman was the Labour Party’s most senior official under former prime minister Tony Blair, before going on to serve as a government minister from the House of Lords under both Mr Blair and Gordon Brown.
He later served as chairman of the Football Association, but left the role in 2010 following reports he had accused Spain and Russia of plotting to bribe referees.
In his resignation letter, published on Twitter by BBC Newsnight on Tuesday, the 75-year-old wrote: “Day by day the extent and depth of antisemitism becomes clearer in the top leadership and National Executive Committee.
“Antisemites are shielded and solid and serious party members are thrown out unceremoniously.
“And each new manifestation is followed by a grim parade of social media messages directed at Jewish party members.
“The experience of life in the party has become sickening.”
He claimed Labour had “slipped into the familiar gutter of so many of the hard left”, adding: “The old tropes about the secret wiring connecting Jewish entrepreneurs and the use of wealth to exercise secretive control can be heard on an almost daily basis.”
Lord Triesman said his decision “has not been about Israel” and explained he “always criticised” the Israeli government during his time as a foreign office minister.
“My decision is straightforwardly about the party leadership’s use of any excuse to allow their allies to attack Jews or to engage with antisemites,” he added.
“My sad conclusion is that the Labour Party is very plainly institutionally antisemitic, and its leader and his circle are antisemitic having never once made the right judgement call about an issue reflecting deep prejudice.
“The number of examples is shocking.”
The peer expressed his “respect” for party colleagues who “hope something will turn up to change it all”, but suggested there is a “unicorn delusion” in such a view.
Ending his letter, addressed to Angela Smith – the shadow leader of the House of Lords, Lord Triesman said: “We may one day be the party of anti-racism once again but it certainly isn’t today.”
Labour strongly disputed Lord Triesman’s claims that “antisemites are shielded” and that “solid and serious party members are thrown out unceremoniously”, highlighting a lack of examples or evidence within his letter.
A party spokesperson said: “We completely reject these false and offensive claims.
“The Labour Party at all levels is implacably opposed to antisemitism and is determined to root out this social cancer from our movement and society.
“Labour is taking decisive action against antisemitism, doubling the number of staff dedicated to dealing with complaints and cases.
“And since Jennie Formby became general secretary, the rate at which antisemitism cases have been dealt with has increased four-fold.
“Our records show that antisemitism cases that have gone through the stages of our disciplinary procedures since September 2015 account for about 0.06% of the party’s membership.
“This represents a tiny minority, but one antisemite is one too many, and we will continue to act against this repugnant form of racism.”
Responding to the peers’ resignations, Labour MP Margaret Hodge posted on Twitter: “Labour peers, MPs, councillors & thousands of party members have been chased out by the rise of vile antisemitism from the hard left.
“Party leadership must stop trying to shut people up and start listening.”