Almost three-quarters of Labour delegates back Momentum proposals to make sitting MPs stand against rivals for reselection, plans that have caused some unease amongst senior Labour shadow ministers.

The grassroots group said the vast majority of delegates attending next week’s Labour conference in Liverpool support their proposals for mandatory reselection, where MPs have to stand in open contests in order to run again for a seat, according to its polling.

After polling more than 1,100 delegates from 450 local Labour parties, Momentum said 72% were supportive of the proposals, with 17% opposed and 6% undecided. A Momentum petition backing the measure has gained more than 12,000 signatures in less than a week.

But senior Labour politicians are understood to be cautious about the proposals, including Jeremy Corbyn loyalists in the shadow cabinet.

Shadow business secretary Rebecca Long-Bailey said it was a “difficult topic” and said the party should be “careful with proposals like this”.

“We want it to be a democratic party, where members feel like they have their say,” she told BBC Radio 5 Live. “But the other side is if an MP had to go through a mandatory reselection process every three, four, five years, their attention would be drawn away from Westminster.

“It needs to be looked at carefully. What I wouldn’t like to see is members of the shadow cabinet doing great jobs in parliament, holding the government to account, [then] having to go through a reselection process, diverting their attention away. Equally, members should have a say, so I do take both views and it will be an interesting discussion if it does make it to the conference floor.”

Shadow chancellor John McDonnell has said he backs the current system of a trigger ballot – where MPs must lose the backing of local branches and affiliates before any reselection process is triggered.

“I think that works quite effectively but that will be a debate – I can’t see it going through, but you never know on these occasions,” he said last week.

Momentum argues that an “outdated rulebook” is holding back new members.

The party’s national co-ordinator, Laura Parker, cited the example of Alexandria Ocasio-Cortez, the 28-year-old Democratic nominee for Congress, stating that if she “had been subject to Labour’s restrictive, outdated rules she would have been shut out”.

“There is an overwhelming desire at the grassroots for a radical democratisation of our party and we ignore that desire at our peril,” Parker said. “If we can’t make democracy work in Labour, we can’t make it work in the rest of society, and we should start by getting our own house in order.

Laura Parker, national organiser of Momentum. Photograph: Christian Sinibaldi/The Guardian

“Measures to open up parliamentary selections, increase grassroots representation on the national executive committee and give members more of a say in leadership contests are supported by a vast majority of ordinary Labour members, and I hope NEC members will take note of this support when they meet on Tuesday.”

Labour’s annual conference is likely to be dominated by debate on the party’s Brexit policy, after an unprecedented number of constituency groups submitted motions calling for the party to back a new referendum.

Of the 272 motions being examined by the party’s conference arrangements committee on Monday, 151 are on the subject of Brexit.

The majority call for the party to adopt a “people’s vote” on the final deal, with template motions drafted by a number of grassroots groups, including the leftwing Another Europe is Possible, Labour for a People’s Vote and the student group FFS (For our Future’s Sake).

The sheer number of motions submitted will mean the party is all but bound to accept Brexit for a topic of debate at conference. Labour chiefs are expected to thrash out a compromise position when delegates meet on the Sunday night of conference to agree a composite motion, which is unlikely to expressly endorse a new poll but may keep such an option on the table.



Michael Chessum, national organiser for Another Europe is Possible, said: “If we don’t have a manifesto commitment for a fresh referendum, we will end up going into an autumn election either promising a ‘bespoke Labour Brexit’, which we have no time to negotiate, or offering a Norway-style deal, which is straightforwardly worse than EU membership and will leave Corbyn with no seat at the European table.”

Mike Buckley, who founded Labour for a People’s Vote, said it was astounding that almost a quarter of constituency parties had submitted motions calling for a new vote on the deal.

“The Labour movement has shifted decisively against Brexit this summer – these motions follow the trade unions’ decision to oppose Brexit and support the principle of a final say,” he said.

On Sunday, the mayor of London, Sadiq Khan, said his party should support a vote on the final deal. “I don’t believe Theresa May has the mandate to gamble so flagrantly with the British economy and people’s livelihoods,” he wrote in the Observer.

However, the shadow international trade secretary, Barry Gardiner, argued that a fresh referendum would give May a lifeline. “Calling for a second referendum is really giving her a lifeline, because then she can say ‘Oh, if I can’t get it through parliament, I’ll go back to the people,’” he said.

Labour would make a judgment later on whether to back any new poll, he said. “The reason we have not ruled anything out is because nobody knows what’s going to happen over the next few weeks.”