Government sources have told the BBC that Turner has had previous written warnings, but the decision to suspend the whip will be kept under review.
Labour sources say there was a “pattern of behaviour” that led to the decision to withdraw the whip, which means he will sit in the House of Commons as an independent.
Turner has been one of the most vocal opponents of the government’s proposal to limit jury trials in England and Wales.
Last year, the MP branded the reform a “stupid idea” and urged Justice Secretary David Lammy to “please God, stop what you’re doing”.
Speaking to Times Radio earlier this month, Turner said he was “already on a conduct warning for having the audacity to say that these proposals are ludicrous”.
“I’m not going to be bullied around,” Turner said.
“If my parliamentary Labour party chief, prime minister, leader of the party or whatever else doesn’t want me in the party anymore, fine. I don’t mind walking and causing a by-election.”
More recently, Turner has commented on the theft of a government phone owned by the prime minister’s former chief-of-staff Morgan McSweeney.
Messages relating to Lord Mandelson’s appointment as British ambassador to the US could be lost as a result of the theft in October last year.
Posting on X, Turner wrote: “I don’t believe McSwindle had his iPhone stolen.”
He offered no evidence for this claim.
But in a later post, he said: “I got the memo now. Morgan McSweeney was mugged, reported that to the police, followed all the processes. Any questions around this is just conspiracy theory territory, really. Let’s move along now.”
Labour sources say Turner’s suspension was not specifically in response to saying last week that he did not believe McSweeney had had his phone stolen.
Turner was critical of McSweeney in an expletive-laden interview with activist and journalist Jody McIntyre last week.
In the interview, Turner cast doubt on McSweeney’s version of events of the phone theft and alleged the prime minister’s former chief of staff was “still running the job” in the background.
A former barrister, Turner was elected as an MP in 2010 and served in the shadow cabinet of former Labour leader Jeremy Corbyn.
He was re-elected in 2024 with an increased vote share of 43.8% and an increased majority of 3,920, with Reform UK’s candidate in second place.
