Tom Watson has called for a special conference to settle Labour’s growing Brexit row by the end of July, as he attempted to push Jeremy Corbyn closer towards a second referendum on Monday.
In a bid to force the Labour leader’s hand, Mr Watson is urging the party’s national executive committee (NEC) to approve an emergency ballot or meeting of members before Parliament rises for the summer.
Challenging Mr Corbyn over his attempts to delay changing policy until Labour’s annual conference in September, Mr Watson said he feared it would be “too late” to prevent a no deal Brexit.
Instead, he is demanding that Labour’s governing body take matters into their own hands by sanctioning a vote by the end of next month, providing enough time for MPs to make the case for a public vote during the summer recess.
The Telegraph understands that Mr Watson will now ratchet up pressure on the NEC to agree to his demands, in a move which threatens to put him on a collision course with Mr Corbyn and his allies.
In a sign of mounting tensions on Labour’s frontbench, party chairman Ian Lavery hit out at Mr Watson over his plans, accusing him of sidelining the views of millions of Leave voters.
In a thinly-veiled swipe, he warned that "ignoring the 17.4m leave voters isn’t politically smart".
It comes a week after Mr Lavery, who has repeatedly clashed with Mr Watson on Brexit, branded Remainers in the party as “left wing intellectuals” who are “sneering at ordinary people”.
Dismissing the allegation, Mr Watson said Labour could not go on “questioning one another’s motives and intentions”.
Speaking in central London, he said: "Some people have begun to equate support for Europe with class identity, I don't think that's right or helpful.
"The majority of Labour people are supportive of Europe - and that support is not dictated by social class."
Setting out his stall against Mr Corbyn, who has insisted Labour is the party of both Leavers and Remainers, Mr Watson argued that the party should be unequivocally in favour of Remain.
“European is who we are and who we have always been,” he continued. “Our members are remain. Our values are remain. Our hearts are remain. We need our Labour Party to be true to who we are and be loud and proud in support of Europe.”
He also challenged Mr Corbyn’s assertion that Labour’s main priority is forcing a general election, adding: “The only tool available to actually break this deadlock - we all know, even if we have not admitted it yet - is a public vote.”
His intervention came as Mr Corbyn was accused by Europhile Labour MPs of going “into hiding”, after a special meeting of Labour’s shadow cabinet was cancelled.
Labour frontbenchers had been due to discuss party’s highly divisive Brexit policy, but were told early on Monday morning that it had been shelved due to a number of individuals being unable to attend.
Accusing the Labour leader of running scared, one MP told PoliticsHome: “Whenever Corbyn has to face difficult questions or issues he goes into hiding. Now the Shadow Cabinet wants to move on Europe, it is also cancelled. He is fast becoming a disappearing act.”