Labour could slash the number of MPs needed to nominate a successor to Jeremy Corbyn, handing new powers to members and trade unions as part of a slew of party reforms briefed to trade unions.

Trade union general secretaries were told this week about the changes set to be proposed at the party conference, the Guardian understands. “This virtually guarantees that a leftwing candidate could succeed Corbyn as leader,” a source said.

The proposals include allowing party members to elect local council leaders.

General secretaries of the major trade unions were given sight of the proposed changes by the Labour chair, Ian Lavery at a meeting on Monday.

Katy Clark, a former MP, is conducting a review into the party’s democratic structures ahead of this year’s conference, which has been billed as an overhaul of how the Labour elects its leadership and selects its MPs.

MPs have traditionally been the guardians of which candidates appear on the final ballot sent to party members. Until last year, MPs needed to get 15% of MPs to nominate them before they were able to stand, reduced to 10% last year.



The provision has meant many of the most left-wing MPs had struggled to secure support from enough like-minded colleagues, with Corbyn eventually nominated in 2015 by MPs who did not share his politics, but who believed they should offer members a wider political spectrum of candidates.



Under the plans set to be presented at the Labour party conference in September, a leadership candidate could circumvent MPs entirely to secure a place on the ballot.



Candidates would be selected if they could secure the support of 10% of trade unions, MPs or party members, plus 5% of each of the other groups.

A 10% threshold could be as few as two or three small unions, and 5% of MPs would be 12 MPs in the current parliament. In 2015, Corbyn needed the backing of almost three times that number of MPs.



The proposals were put to the private “contact group” of the 12 trade unions who affiliate to Labour, a group of union general secretaries who make up the umbrella Trade Union and Labour Party Liaison Organisation (TULO), including Unite, Unison, GMB and the TSSA.

The party is also proposing the removal of the European parliament representative Richard Corbett from the governing national executive committee. Corbett, a Corbyn sceptic, will not end his term as an MEP until the UK leaves the EU in March 2019.

The party is also said to be considering proposals for mandatory re-selection when MPs forfeit their seat in boundary changes but sources denied it was discussed at the meeting on Monday.

MPs whose seats are lost in boundary selection would not win the automatic right to a new seat but would be expected to face an open selection process. The current policy is that MPs, where the majority of their old constituency is in a new seat, are automatically shortlisted.

The government’s proposed boundary changes, authored before the last election, could affect more than 200 Labour MPs and see 30 Labour seats disappear.

They would be likely to significantly affect high-profile MPs including Corbyn himself, shadow ministers Diane Abbott and Kate Osamor, as well as Yvette Cooper, Alison McGovern and Owen Smith. However, since the 2017 general election, reforms have been put indefinitely on hold.

Another proposed reform is for party members to chose the leaders of their local Labour council groups, taking the power to nominate the leader away from the groups. “With the current membership this would see dozens of group leaders removed in favour of more pro-Corbyn councillors,” one source said.

The final deadline for submissions to Clark is on Friday. Union chiefs are expected to meet again in the coming weeks, ahead of the NEC meeting on 17 July.

Corbyn and his allies have always favoured giving party members, the majority of whom support his leadership, a greater say in how the party is run. However, the Labour leadership may face a Brexit backlash at conference, with recent research showing that three quarters of Labour party members want a “People’s Vote” on any Brexit deal. Activists from 62 local Labour parties have pledged to raise the issue in a motion at the party’s conference.

A Labour party spokesperson, said: “Labour’s Democracy Review has received submissions from thousands of members who have proposed a wide ranging set of ideas and proposals.

“The deadline for submissions is still ongoing and any final recommendations or changes to the party rule book will be agreed by Labour members at party conference.”