High-profile allies of Jeremy Corbyn are set for a selection showdown for the plum London seat of Vauxhall after the Brexit-backing Labour MP Kate Hoey announced she would stand down at the next election in her ultra-remain constituency.

Hoey’s announcement came on the day of Labour’s deadline for MPs to declare their intentions for the next election.

Friends of the former MP Katy Clark, a key ally of the Labour leader who was tasked with undertaking a review of party democracy, said she intended to put her name forward.

Barring any restrictions, Clark is likely to face competition from one of Momentum’s most senior figures, Laura Parker, the leftwing grassroots group’s national coordinator.

Both women are prominent members of the south London constituency party and were candidates in London at the European elections. Both failed to get elected because of the Liberal Democrat surge in the capital.

Labour sources said the party would favour a minority ethnic candidate and could aim to produce an all-BAME shortlist. Others who have been tipped for the seat include İbrahim Doğuş, a Kurdish entrepreneur and founder of the annual Kebab Awards, and Florence Eshalomi, a member of the London assembly.

Eshalomi is also believed to be also considering a run for Labour in Streatham, where the current MP, Chuka Umunna, has defected to the Lib Dems.

Hoey, who has consistently voted with the government to stop efforts to secure a soft Brexit or to oppose no deal, was subject to a no-confidence vote last summer in Vauxhall, where 77.6% of voters backed remain in the 2016 referendum. At the time Hoey, who has held the seat since 1989, said she would not let it change the way she acted in parliament.

She campaigned in 2016 with Nigel Farage’s Grassroots Out, including posing with the then Ukip leader on a boat on the Thames. Local anger grew when Hoey put her name to an amendment to the customs bill put forward by the pro-Brexit European Research Group (ERG) ruling out a customs border in the Irish Sea.

She was one of four Labour MPs to support the government in defeating an amendment calling for a post-Brexit customs union. Hoey did not support Theresa May’s Brexit deal on the grounds that it was too soft.

Though the no-confidence motion had no force, Hoey might have faced a reselection battle in her constituency after rule changes last September made it easier for members to force a trigger ballot, which would require an MP to compete against other candidates for reselection.

The seat has a 20,250 Labour majority but has been heavily targeted by the Liberal Democrats because of Hoey’s Brexit views, meaning the constituency party is likely to select a candidate with pro-remain credentials.

In a surprise move on Monday, the former shadow education secretary Stephen Twigg also said he would stand down. Twigg, the MP for Liverpool West Derby, who was on the shadow frontbench under Ed Miliband, wrote to his constituents saying he wanted to seek new opportunities outside parliament.

In his letter, Twigg stressed the importance of Labour remaining a “broad church” and keeping “an open and respectful culture”. He wrote: “I have spent most of the past 30 years of my life as an elected representative. As I approach my mid-50s I want to have the opportunity to take on something new.”

Stephen Pound, the veteran MP for Ealing North, has told his local party he will stand down. Three other MPs who have either backed May’s Brexit deal or opposed efforts for a second referendum have already announced they will stand down: Poplar and Limehouse’s Jim Fitzpatrick, Rother Valley’s Kevin Barron and Blyth Valley’s Ronnie Campbell.