Diane Abbott, the Labour leftwinger, suggested that Ed Miliband is “pandering to anti-immigrant sentiment” after she was sacked from the Opposition's frontbench team.

Britain's first black woman MP was dismissed as Labour's public health spokeswoman for not showing the “discipline” expected of her. Last month, she threatened to resign when it appeared that Mr Miliband was ready to support David Cameron by backing military intervention by the UK in Syria.

Labour sources said her departure was “by mutual consent” but did not dispute her statement that Mr Miliband wanted more “message discipline.” They accepted that Labour had hardened its line on immigration.

Ms Abbott, who ran for the Labour leadership in 2010, said: “I have long despaired of the downward spiral of Labour's rhetoric on immigration. For instance we should have come out against the 'immigrants go home' van far more quickly and more firmly than we did. Unfortunately the people around Miliband are terrified by the polling on immigration and have convinced him that we have to move right on the issue. My settled view is that there no votes for the Labour party in pandering to anti-immigrant sentiment.”

The outspoken MP for Hackney North and Stoke Newington said Labour should offer “a more far-reaching critique of austerity” and consider scrapping the Trident nuclear missile system. She added: “I have enjoyed being on the frontbench. But I plan to enjoy being a free agent on the backbenches even more.”

As Mr Miliband completed his reshuffle, Ms Abbott was succeeded by Luciana Berger. He continued to promote women to his frontbench team, with Shabana Mahmood, one of three Muslim women MPs elected in 2010, joining Ed Balls's shadow Treasury team and Lucy Powell becoming children's spokeswoman.

David Hanson was made immigration spokesman, Gareth Thomas took over the Europe brief and Jack Dromey is the new spokesman on policing.