THE front-runner to replace a Labour councillor is a senior Labour Party official who worked as trade union liaison for Jeremy Corbyn.

Nancy Platts, a former Labour prospective parliamentary candidate in the city, is understood to be the likeliest candidate to replace Lloyd Russell-Moyle MP.

The MP last week announced his decision to step down from the city council seat he also holds, at the end of this year.

The by-election for his East Brighton council seat will be closely watched as a bellwether for potentially fraught Labour reselection battles next spring.

Both Ms Platts and Mr Russell-Moyle are strong supporters of Jeremy Corbyn, but a big win for Ms Platts might spell trouble for the more centrist Warren Morgan, who represents the same ward.

Cllr Morgan, like all Labour councillors, will have to fight for reselection on the same terms as any possible challenger.

The leftwing pressure group Momentum is increasingly strong in the East Brighton area and its motivated supporters were instrumental in delivering Mr Russell-Moyle’s huge 10,000 vote majority in June, when he unseated Tory incumbent Simon Kirby,

Nancy Platts confirmed to The Argus she was standing as a candidate for the by-election expected in February.

Ms Platts’ name will be well known to the city’s politicos. She was narrowly defeated by Simon Kirby in her bid to represent Brighton Kemptown in 2015, and lost to Caroline Lucas in Pavilion five years earlier when the Green Party won its first and only Westminster seat.

After the 2015 election Ms Platts took a role as Jeremy Corbyn’s trades union and National Executive Committee manager, working with the new leader in London although she continued to live in and commute from Brighton.

She is now self-employed in a social enterprise firm which offers low cost communications support and advice to trades union and charities.

Last week Mr Russell-Moyle wrote to party members to inform them of his decision.

He told The Argus that after six months in both roles it was right to step down, and to allow his replacement to play a role in February’s council budget negotiations.

Potential Labour candidates for the ward should put their names forward by Thursday, with a hustings scheduled for December 21.