The Green Party leadership briefly contemplated postponing its flagship autumn conference to pour resources into Zack Polanski’s tilt at Holborn and St Pancras, party officials have confirmed, underscoring the high stakes of a by-election that has become a proxy battle for the soul of the progressive vote.
Polanski, who took the Green helm just over a year ago, will contest the seat vacated by Sir Keir Starmer’s resignation as prime minister and MP earlier this month. The vote, set for 8 October, pits the Green leader directly against Sagal Abdi-Wali, the leader of Camden Council and Labour’s chosen standard-bearer. A victory would hand the Greens a sixth MP, building on their breakthrough in Gorton and Denton earlier this year.
Conference dilemma
The party’s two-day gathering in Brighton, scheduled for 2–4 October, is on track to be the largest in Green history. Thousands of members are expected, buoyed by a surge in membership and electoral performance since Polanski’s elevation. Yet the proximity to the by-election — just days before polling day — forced a strategic reckoning at the top of the party.
“One possible option was to postpone our conference,” a Green Party spokesperson acknowledged. “The party was exploring different ways of allocating our resources effectively while fighting the Holborn and St Pancras by-election.”
After internal discussion, the leadership concluded that cancelling or delaying the conference would send the wrong signal. The spokesperson added: “After discussion we remain committed to running an incredibly ambitious Holborn and St Pancras by-election campaign and holding what will be our biggest ever party conference.”
Labour’s litmus test
For Labour, the contest is more than a defensive operation. Sources close to Andy Burnham, who succeeded Starmer in Downing Street, describe the by-election as a critical barometer before any decision on an early general election. The Prime Minister’s strategists want to know whether the Green surge that plagued Labour under Starmer has receded with the change of leadership.
The memory of Gorton and Denton looms large. There, the Green candidate Hannah Spencer pushed Labour into third place behind Reform UK — a humiliation that shook the party’s confidence in its urban strongholds. One Labour source put it bluntly: “Because Keir’s seat was a target and Polanski is running in it, this gives the PM a perfect opportunity to see if the Green threat has gone with a change of leader.”
That same source claimed Labour is already seeing “people come back [from the Greens] to Labour. Under Keir, there was no doubt that we were losing lots of supporters and party members to the Greens.”
Polanski’s gamble
Polanski’s candidacy represents a calculated risk. A leader standing in a by-election is unusual; a loss would be a personal blow and could stall the party’s momentum. But the potential reward — a sitting party leader in the Commons, a sixth MP, and a symbolic victory in the former prime minister’s own seat — could reshape the parliamentary arithmetic and the media narrative.
The Greens have poured organiser hours, digital infrastructure and volunteer capacity into the constituency. Polanski himself has been a near-constant presence on the streets of Camden, holding surgeries in community centres and debating housing, climate and the cost of living on doorsteps where Labour has dominated for decades.
Abdi-Wali, for her part, brings the machinery of a long-established Labour operation and the advantage of incumbency at council level. Her campaign has leaned heavily on the “change delivered” message — new leadership, new direction — while warning that a Green win would destabilise a Labour government still finding its feet.
Why it Matters
Holborn and St Pancras has become the crucible for a deeper realignment on the British left. If Polanski wins, it confirms that the Green Party is no longer a pressure group but a parliamentary force capable of taking seats from Labour in its metropolitan heartlands — and that Burnham’s “reset” has failed to stanch the bleeding. If Labour holds, it validates the new leader’s claim to have reunited the progressive coalition and clears the path for an early election. Either outcome will reverberate far beyond the boundaries of a single north London constituency.
