Keir Starmer has suspended four rebel Labour MPs over breaches of party discipline.
Brian Leishman, Chris Hinchliff and Neil Duncan-Jordan - all elected just last year - and Rachael Maskell will now sit as Independents in the House of Commons. It is understood the four MPs met with the Chief Whip today, where they were told they would be suspended for repeated breaches of party discipline, pending a future review.
They were among dozens of Labour backbenchers to vote against the government earlier this month on disability benefit cuts - plans now abandoned after a massive revolt. Rosena Allin Khan, Bell Ribeiro-Addy and Mohammed Yasin have all been removed from their trade envoy roles - a lesser punishment.
Mr Duncan-Jordan, the MP for Poole, was among 42 Labour MPs to sign a letter earlier this year warning the PM cuts to disability benefits were "impossible to support".
He was also critical of the cuts to winter fuel payments for millions of pensioners before a major government U-turn last month.
He told The Mirror today: "Since being elected I have consistently spoken up for my constituents on a range of issues, including most recently on cuts to disability benefits. I understood this could come at a cost, but I couldn’t support making disabled people poorer.
"Although I’ve been suspended from the Parliamentary Labour Party today, I’ve been part of the Labour and trade union movement for 40 years and remain as committed as ever to its values. To my constituents: it’s business as usual. I remain your hardworking local MP, I will continue to take up your concerns and speak up for Poole."
John McDonnell, who had the Labour whip suspended almost a year ago for voting against the government over the two-child benefit limit, responded: "What a considered and dignified response from Neil Duncan-Jordan to his suspension from the Labour Whip. Speaking up for his constituents & following his conscience are the crimes he committed."
Ms Maskell, the York Central MP, said she had been suspended from the party for "standing up for my constituents" over welfare reform. "The reason why I voted the way I did was because I believe in fighting for people," she added.
She said she had had a "positive conversation" with the Chief Whip, adding: "He knows my heart and why I did what I did. I explained there are lines I can't cross because of where I come from in politics with my faith."
She said she was "not angry" but "upset that we are in this place because I believe we are better than that as a party. I believe that strength comes from the backbenches."
Ms Maskell urged the Prime Minister to engage with his backbenchers, saying she wanted to see "bridges built" and this would "make him a better Prime Minister." She said she believed there was a path back to having the Labour whip restored. But she said she did not "believe in the process of suspension", adding it was "better to have dialogue".
All the rebels have spoken out against the Government on various issues.
Mr Duncan-Jordan and Mr Leishman were vocal critics of the disability benefit cuts. Ms Maskell tabled an amendment to the government's welfare plans, which was supported by over 40 Labour MPs.
Mr Hinchliff led a rebellion on the Planning Bill last month, with an amendment hat would have imposed new environmental obligations on developers.
Mr Leishman has also been vocal about the closure of the Grangemouth oil refinery in his constituency.