The Green Party is celebrating its “second best ever by-election result” in parliamentary history. Securing a massive 33% of the vote in the North London constituency of Holborn and St Pancras, Green Party Leader Zack Polanski more than tripled the party’s 2024 vote share, marking a spectacular 22 percentage point increase. The high-profile by-election took place following the decision of the seat’s former representative—and former Labour Prime Minister—Keir Starmer to stand down as an MP.
Speaking to BBC Breakfast, Polanski acknowledged his disappointment at not winning but stressed that he was “incredibly proud” of the historic surge. This performance sits second only to Hannah Spencer’s stunning victory over Labour and Reform in Gorton and Denton earlier this year. The Green Party’s capacity to disrupt Labour strongholds was highlighted by independent pollster John Curtice, who noted that “the Green Party are more of an electoral threat in these seats than we’ve ever been before.”
“People Voted Green and Then We Moved Labour”
The Green Party’s structural impact on UK politics has intensified throughout 2026. During the local elections in May, the Greens won heavily in traditional Labour heartlands, taking four times as many votes from Labour as Reform UK did, a momentum that ultimately pushed Keir Starmer out of No. 10. With a new Prime Minister in Downing Street, the Greens’ strategy remains unchanged: leverage voter support to force political concessions.
“People voted Green and then we moved Labour,” Polanski told Sky News. The campaign’s core demands—introducing strict rent controls, nationalizing the failing Thames Water utility, and keeping fossil fuels in the ground—resonated deeply with local residents. This pressure forced a defensive shift from the government; rumors suggest Prime Minister Andy Burnham deliberately delayed a controversial decision to greenlight new North Sea oil and gas drilling until after polling day out of fear of losing votes to the Greens. Furthermore, successful Labour candidate Sagal Abdi-Wali explicitly pledged during the race to oppose new oil and gas and to pressure the Prime Minister to nationalize Thames Water.
Testing Burnham’s Rhetoric Against Reality
Despite Prime Minister Burnham’s previous high-profile calls to end forty years of neoliberalism, the Green Party warns that his administration is already cooling on the idea. According to his own Chancellor, John Healey, the new cabinet is operating primarily as a “continuity” government.
Challenging the Prime Minister’s direction, Polanski stated: “The real question now is: Does Andy Burnham really want to end neoliberalism? And if he does, why has he ruled out rent controls? Why is he talking about public control of water companies, rather than national ownership? What we’re seeing is rhetoric. What we’re not yet seeing is action.” The Greens maintain that their historic second-place finish in Starmer’s former seat proves that sustainable left-wing policy shifts can only be achieved by keeping the electoral pressure on through a strong Green vote.
