Labour activists who want a second referendum are seeking selection by the party to fight for seats in the European Parliament.
The move is intended to influence Jeremy Corbyn and the party’s manifesto for the elections due to be held on May 23.
Amatey Doku, Kira Lewis, Luke Myer, Elsie Greenwood and Chris Morris have put in their applications to become Labour MEP candidates for London, North West, Scotland and Yorkshire and Humber, respectively.
The five are members of For our Future’s Sake – a youth movement which is part of the People’s Vote campaign.
Labour is due to have selected all its MEP candidates by Wednesday.
Myer said “young, pro-public vote, voices” needed to be heard by the party leadership as it prepared for the elections.
Greenwood said campaigners had spent the last year ensuring Labour in Scotland had moved its position on Brexit.
“These elections are our opportunity to solidify our support for a public vote,” she said.
In London, two close allies of Corbyn are already battling for a London seat.
Laura Parker, the national coordinator of the grassroots group Momentum, and Katy Clark, a former MP and political secretary to Corbyn, are both in contention.
The party is split over how forcefully to push for a second referendum and Corbyn himself has appeared lukewarm, at best, to the idea.
The UK will be legally bound to hold the elections if the government has not managed to get a Brexit deal through parliament in time.
Labour has been engaged in talks with the government in order to see if the deadlock in parliament can be broken. However, there is little sign an agreement is on the horizon.
Many Conservatives are worried the party will face a wipeout if it has to fight the elections.
Jeremy Hunt, the foreign secretary, acknowledged on Monday the Tories could be heading for a “disastrous” showing at the polls.
Nigel Farage will be hoping his new Brexit Party will be able to capitalise on eurosceptic frustration that the UK is still a member of the EU.
Meanwhile the smaller avowably pro-EU parties such as the Lib Dems and the breakaway Independent Group are hoping their support for a second referendum will win them the ‘Remain’ vote.