Labour's Tom Watson is facing a fresh bid to oust him as deputy leader by abolishing his post.
Labour's Tom Watson has said the bid to oust him as deputy leader by abolishing his post is a "sectarian attack" on the party's "broad church".
An initial move was made at the party's National Executive Committee (NEC) meeting on Friday but it failed to get the two-thirds majority needed.
He told the BBC he found out late on Friday in a text message that a motion had been tabled by Jon Lansman, founder of Labour grassroots group Momentum.
A further attempt is set to be made on Saturday at the party's conference.
Members had voted him in and should be able to vote him out, he said.
It is understood the motion was tabled by Jon Lansman, founder of Labour grassroots group Momentum.
Mr Watson has been at odds with leader Jeremy Corbyn over the party's stance on Brexit but said he had to speak out.
The campaign group was set up to support Jeremy Corbyn's leadership of the Labour Party.
An initial move to oust him was made at a meeting of the party's National Executive Committee (NEC) on Friday but it failed to get the two-thirds majority needed.
Mr Watson, who has urged Labour to "unequivocally back remain", has been at odds with Mr Corbyn over the party's stance on Brexit.
A further attempt is set to be made on Saturday at the party's conference in Brighton.
He wants another public vote on the UK's membership of the EU before any general election, but Mr Corbyn has said an election should come first.
Speaking to Radio 4's Today programme, Mr Watson said he found out about the move while having a meal at a Chinese restaurant in Manchester on Friday night.
The party leader has refused to say which side he might back in a future Brexit referendum under a Labour government.
He called it a "straight sectarian attack on a broad church party, moving us into a different kind of institution".
He said he felt that Mr Lansman "and his faction" were so angry about his position on Brexit they would "rather abolish me than have a debate about it".
Asked if he thought the move had been made by Mr Corbyn himself, Mr Watson said "I don't know", but added his leader had the power to stop it.
Mr Watson has urged Labour to "unequivocally back remain" and had said he wants another public vote on the UK's membership of the EU before any general election.
But Mr Corbyn wants to hold another referendum once Labour has won power, in which voters would have the choice to remain in the EU alongside a "credible" Leave proposal.
A Momentum source told the BBC: "We just can't afford to go into an election with a deputy leader set on wrecking Labour's chances.
A Momentum source told the BBC: "We just can't afford to go into an election with a deputy leader set on wrecking Labour's chances.
"Labour members overwhelmingly want a deputy leadership election, but our outdated rulebook won't let it happen."
"Labour members overwhelmingly want a deputy leadership election, but our outdated rulebook won't let it happen."
Dawn Butler, shadow women and equalities secretary, said the post of deputy leader was a good one and she was "quite surprised" that the motion had been brought.
Dawn Butler, shadow women and equalities secretary, said Momentum's move had "come out of the blue" but she could understand the frustration with the deputy leader.
"It just came out of the blue for me," she told the BBC Radio 4's Today programme.
She said she did not believe it was an attempt to silence Mr Watson.
"Lots of people are very frustrated at not seeing the deputy leader at meetings or not being able to communicate with [him]," she added.
Asked if Mr Watson was doing the job well, she said: "I have my frustrations with Tom too. I haven't seen him at a shadow cabinet meeting for a while."
Asked if Mr Watson was doing the job well, she said: "I have my frustrations with Tom too. I haven't seen him at a shadow cabinet meeting for a while."
BBC political editor Laura Kuenssberg says Momentum's move to abolish Mr Watson's role "was not discussed" among its governing body adding there was "anger" at Mr Lansman as this was "not an official decision".
The NEC, Labour's governing body, is set to vote again on abolishing Mr Watson's post at the party's annual conference at 10:00 BST on Saturday.
The NEC, Labour's governing body, is set to vote again on abolishing Mr Watson's post at the party's annual conference at 10:00 BST on Saturday.
There will then be a vote on the conference floor in the afternoon, where the bid could be approved, ousting Mr Watson.
There will then be a vote on the conference floor in the afternoon, where the bid could be approved, ousting Mr Watson.
Analysis
BBC political editor Laura Kuenssberg says Momentum's move "was not discussed" among its governing body - adding there was "anger" at Mr Lansman as this was "not an official decision".
By Jessica Parker, political reporter
Conferences are supposed to be a chance for a party to showcase its policies and portray unity - especially when a general election could be around the corner.
But the news of this effort to oust Tom Watson - by abolishing the job he was elected to - has sparked a spectacular clash as members gather in Brighton.
A "farcical distraction"? Needlessly "self-destructive"? That's certainly what some infuriated Labour MPs think.
But it's also true to say that Tom Watson has his fair share of critics. Those who think that the deputy has repeatedly undermined the leader, not least by straying on Brexit policy.
So is Tom Watson's downfall imminent? Not quite. A lot could yet happen - and even those who aren't keen on the current deputy might wonder whether this is the best way to kick off the Labour Party Conference.
A number of Labour MPs, including former leader Ed Miliband, have condemned the bid to oust Mr Watson.
He tweeted that those who had come up with the idea to abolish the deputy leader post had "taken leave of their senses".
Neither Mr Corbyn nor Mr Watson were at Friday's NEC meeting.
A senior Labour source said: "Tom had given his apologies to the NEC... as he had to look after his children.
"Usually when you disagree within parties on issues like taking a remain stance on Brexit, you have a debate. Seems that in Jeremy Corbyn's Labour Party they'd rather abolish you than debate with you."
Labour MP Wes Streeting said in a Twitter post the push to oust Mr Watson "isn't just outrageous, it's self destructive".
"Labour Conference this week needs to put the party on a general election footing - talking to the country about our vision for Britain," he wrote.
Labour MP Jess Phillips tweeted: "Wish that we could just stop pretending & say what we think... There's a desperate attempt to control & expel anyone who has an independent thought.
"I'm so sick of pretending just say you hate Tom Watson just be honest."
Under Labour Party rules, a candidate may seek nominations to trigger a deputy leadership election each year prior to the annual party conference.
But nominations which do not gain the backing of 20% of Labour MPs and MEPs will not be taken forward.
