Britain's center-left Labour Party lost a traditionally safe seat in Manchester to the Greens in a closely watched parliamentary byelection after votes were counted on Friday.

The result adds pressure on Prime Minister Keir Starmer amid declining approval ratings and renewed political controversy linked to late convicted US sex offender Jeffrey Epstein.

How did the vote pan out?

Green candidate Hannah Spencer won the Gorton and Denton constituency with nearly 15,000 votes, according to official results released Friday, while Labour finished third behind Reform UK.

Spencer, a 34-year-old plumber and trainee plasterer, campaigned partly on her party's pro-Palestinian stance, appealing to Muslim voters who make up about 28% of the constituency's population. Her victory raises the Greens' total representation in parliament to five seats.

Right-wing populist Reform UK candidate Matt Goodwin secured around 10,500 votes, while Labour's local councilor Angeliki Stogia received just over 9,300. Labour won the seat less than two years ago with a 13,000 majority.

The Conservative Party, traditionally one of the two main parties of government in modern Britain, managed just 706 votes.

Labour's leadership had blocked a potential candidacy by Manchester Mayor Andy Burnham, widely seen as a possible internal challenger to Starmer.

The byelection was triggered after the previous Labour member of parliament for the area resigned for health reasons.

The Gorton and Denton constituency has been described as a "Frankenstein's monster," being geographically and demographically incongruous. It straddles municipal boundaries with an electorate seen to split three ways — student, Muslim and white working class.

What does the result mean?

The result adds pressure on Starmer amid declining approval ratings and renewed political controversy over his appointment of prominent Labour figure Peter Mandelson as UK ambassador to the US — despite Mandelson's past contacts with Epstein.

Starmer has faced calls to resign, though he has said he intends to remain in office.

Labour chairwoman Anna Turley called the result "clearly disappointing." 

Starmer has sought to target the anti-immigration Reform, led by eurosceptic firebrand Nigel Farage, which leads national polls, by beefing up Labour's policies and rhetoric on immigration.

However, his stance has alienated much of the party's left-wing base and young people, with the Greens capitalizing on the disgruntlement among more progressive voters.

With polling not looking good, a key test for Starmer will be how Labour fares in local elections in Scotland, Wales and London to be held in May. The UK's next general election is not expected until 2029.

Edited by: Rana Taha