Debbie Abrahams has been sacked from Labour’s shadow Cabinet after an investigation into workplace bullying, a party spokesman said.
The Oldham East and Saddleworth MP faced claims by multiple complainants that are understood to have been supported by several witnesses.
But Ms Abrahams said she strongly denied the allegations and criticised the investigation.
She said: “I strongly refute the allegations of bullying made against me. I believe the investigation was not thorough, fair or independent.
“I will continue to represent the people of Oldham East and Saddleworth, and to hold this Government to account, from the back benches.”
Labour said in March that Ms Abrahams had “stood aside from her frontbench role while the Labour Party investigates an employment issue”.
But the MP said at the time she had not agreed to stand aside as shadow work and pensions secretary, and claimed she had been a victim of a “bullying culture of the worst kind”.
An investigation upheld the complaints made against her and found she had engaged in a pattern of bullying behaviour towards staff, it is understood.
Ms Abrahams has been referred to the disputes committee of Labour’s ruling National Executive Committee.
At the time of her suspension she issued a bombshell statement rejecting the allegations against her in the “strongest possible” terms and turned her fire on Jeremy Corbyn, accusing “certain individuals” in the leader’s office of “aggressive, intimidating and wholly unprofessional” behaviour.
A Labour Party spokesman said: “After a thorough party investigation into allegations of workplace bullying, Debbie Abrahams has been referred to the NEC disputes committee.
“She has been relieved of her post as shadow work and pensions secretary.”