Jeremy Corbyn will come under pressure over his Brexit position next week, as 90% of the motions submitted to Labour’s conference call for the party to back Remain in any second referendum.
The Labour leader has pledged to hold another public vote should he become prime minister.
But he has stopped short of guaranteeing he would campaign for the UK to remain an EU member.
An analysis of the motions submitted to the party’s conference due to be held in Brighton showed that of 90 motions submitted, 81 call on Labour to back Remain.
A majority of motions back also revoking Article 50 if necessary to prevent a no-deal Brexit.
Labour MP Marsha de Cordova, the shadow minister for disabled people, warned “there is no middle ground when it comes to campaigning in an EU referendum”.
“We tried to fudge our line before and failed dramatically. Our members and activists won’t forgive us if we do that again. It’s time to take a side and expose Brexit as the completely destructive Tory project it is,” she added.
It comes as the Lib Dems on Sunday formally adopted revoking Article 50 should the party form the next government in an attempt to scoop up the pro-EU vote.
The fight over whether Labour should go into the next general election pledging to campaign for Remain will likely dominate the conference.
Several high profile Labour figures including John McDonnell, Diane Abbott, Keir Starmer, Nick Brown and Emily Thornberry have all said they will back Remain.
But other figures have warned adopting an explicitly pro-EU platform could alienate voters who backed Leave at the 2016 referendum.
Unite boss Len McCluskey reportedly clashed with McDonnell recently over the shadow chancellor’s repeated pro-Remain interventions.
Michael Chessum, national organiser for the pro-Remain Another Europe is Possible group, said Labour’s party members were Corbyn’s “secret weapon” at the upcoming election.
“The party ignores them at its peril,” he said. “Support for an explicit Remain stance is evidently overwhelming.
“If backroom maneuvers are deployed to stop this being debated on conference floor will be a disaster for morale and for Labour’s prospects. We need a debate and a vote at conference. Only if Labour can get clarity on this part of its policy can fight the election on its domestic agenda.”