The Labour Party’s ruling body is to consider abolishing the post of deputy leader.
According to two party officials, Momentum founder Jon Lansman, a key ally of leader Jeremy Corbyn, brought the motion, citing deputy leader Tom Watson’s disloyalty over Brexit.
The chair of Labour’s National Executive Committee ruled the motion should be thrown out but it is likely to go back before the committee today.
A party spokesman did not comment but a source close to Mr Watson told PA news agency that the situation was “completely outrageous”.
Mr Watson recently called for a new Brexit referendum to be held before a general election.
Mr Corbyn, on the other hand, says Labour will offer people a second referendum only after an election.
Earlier this month, Mr Watson said his party must “unambiguously and unequivocally back remain” but Mr Corbyn has always been more cautious about this approach.
Others in Labour also criticised the move against Mr Watson.
The party “should be about putting forward a strong, unified message and showcasing the policies that will win that election”, said Justin Madders, a Labour MP.
Former Labour leader Ed Miliband tweeted: “The move to abolish the deputy leader post without warning or debate is undemocratic, wrong and should not happen.
“Those who came up with the idea for the eve of Labour conference have taken leave of their senses.”
Ex-minister Yvette Cooper tweeted: “This is completely mad and incredibly destructive. Country faces serious challenges and general election could be imminent. @UKLabour conference should be about country and about pulling together. Instead we get this.”
Labour MP David Lammy tweeted: “Tribal infighting in the middle of a Boris Johnshon-inspired national emergency makes me want to weep.
“My constituents and millions of others across the country desperately need the Labour party united right now. The Tories, not Tom Watson, are our opponents. Let’s fight them.”
Former Conservative MP Anna Soubry, who defected earlier this year and is now leader of The Independent Group for Change, tweeted: “If @jeremycorbyn and his gang can’t tolerate @tomwatson #Corbyn is hardly likely to be a credible ‘caretaker’ PM – the leader of a Government of National Unity.”
Labour’s party conference begins today in Brighton and Mr Corbyn is likely to come under pressure to be more active in backing those who want to remain in the EU.
But some party members fear this will result in a loss of support from Brexit voters in places such as northern England.
The Labour Party’s ruling body is to consider abolishing the post of deputy leader. According to two party officials, Momentum founder Jon Lansman, a key ally of leader Jeremy Corbyn, brought the motion, citing deputy leader Tom Watson’s disloyalty over Brexit. Mr Watson recently called for a new Brexit referendum to be held before a general election.