Labour’s National Executive Committee (NEC) has ruled that former leader Jeremy Corbyn cannot stand for the party at the next General Election.
The NEC voted 22 to 12 to approve the motion from current leader Sir Keir Starmer.
There is no right of appeal.
Mr Corbyn – a Labour MP for 40 years – said the decision was a “shameful attack on party democracy”.
A defiant Mr Corbyn said the vote showed “contempt” for Labour voters during the 2017 and 2019 elections – both lost under his leadership.
He added: “I have no intention to stop fighting for a fairer society on behalf of the people of Islington North.
“Sir Keir has instead launched an assault on the rights of his own Labour members, breaking his pledge to build a united and democratic party.”
The motion approved by the NEC states that allowing Mr Corbyn to stand would “significantly diminish” Labour’s chances of “winning the next general election”.
It continues: “It is not in the best interests of the Labour Party for it to endorse Mr Corbyn as a Labour Party candidate at the next general election,”
From 2016, Sir Keir was a key member of Mr Corbyn’s shadow cabinet, speaking for the party on Brexit.
Mr Corbyn was suspended as a Labour MP in 2020 after he said the level of antisemitism within Labour had been “dramatically overstated”.
The Islington North Constituency Labour Party said it “rejects the NEC’s undue interference” in who it chooses as an MP.
It added: “The NEC vote undermines our goal of defeating the Conservatives and working with our communities for social justice.
“We believe in the democratic right of all constituency parties to choose their prospective parliamentary candidate.”