Doncaster MP Rosie Winterton has been sacked as Labour's chief whip after six years in the job.
The Labour leader Jeremy Corbyn has replaced Ms Winterton with Nick Brown, who served as a whip under former PM Gordon Brown.
In a statement released on social media, Mr Corbyn said: "I welcome Nick’s agreement to serve as chief whip to the parliamentary Labour party.
“I would like to pay tribute to Rosie Winterton for her six years’ exceptional service as Chief Whip. She has played an outstanding role in her support for me as leader and for the Labour Party as a whole.”
Earlier this year Ms Winterton protested to Mr Corbyn after a so called 'loyalty list' of Labour MPs was leaked.
The controversial list put MPs into a number of categories, including those who were not seen as being loyal to the leader.
She said the list was 'unacceptable'.
Ms Winterton was elected to the Doncaster Central constituency in 1997.