Veteran Labour MP Dame Margaret Hodge is facing a re-selection battle after activists in her east London constituency voted for the chance to pick a new candidate.
Dame Margaret – an outspoken critic of Jeremy Corbyn – said she was “disappointed” by the result but will fight to keep her Barking seat.
She is the second Labour MP to be “triggered” through the party’s new ballot procedures which make it easier for local members to force a contest.
The Labour Party has come under fire over the move former and deputy leader Harriet Harman said she was “dismayed more than I can say” by the vote.
In a statement, Dame Margaret said: “I am obviously disappointed. My priority remains serving the people of Barking as I have done for the last 25 years.
“At a vital time for the country, with a general election looming, we should be focusing our efforts on holding Boris Johnson and the Tories to account.
“I will work to secure the full backing of Barking Labour Party, so I can continue to play my part as their MP in doing that.”
Dame Margaret, who is Jewish, has angered some in the party for her criticism of Labour’s response to complaints of anti-Semitism.
On one occasion she told Mr Corbyn to his face that he is an “anti-Semite and racist”.
Mike Katz, chairman of the Jewish Labour Movement, said the trigger ballot vote is a “shameful moment” for the party.
“Margaret Hodge has been a steadfast campaigner against racism, fascism and intolerance throughout her political life,” he said.
“She saw off the BNP in Barking and has over the last few years been determined in her opposition to anti-Semitism within the Labour Party.
“This is a shameful moment for a party which claims to embody the values of equality and diversity.
“She has been the target of vicious smears, derision and anti-Semitism, because she has been resolute in her opposition to anti-Jewish racism.”
Labour’s former deputy leader Harriet Harman said she was “dismayed more than I can say” by the vote.
She tweeted: “Margaret Hodge, scourge of tax avoiders, racists and anti-Semitism. Champion of progressive policies. Hyperactive local MP. Surely this cannot stand!”