LONDON — Zack Polanski, the Green Party’s firebrand new leader, is vowing to take the fight to political rivals right and left. 

But first, the Greens have to stop fighting among themselves. 

Taking the stage at a community center near London’s South Bank Tuesday, Polanski, a member of the London Assembly and self-styled “eco-populist,” promised to pursue “bold politics” in the battle against Keir Starmer’s Labour government and Nigel Farage’s surging populist Reform UK. 

The pledge came after a tetchy leadership contest. In the end, Polanski crushed the joint ticket of MPs Adrian Ramsay and Ellie Chowns, winning over 80 percent of the vote. The race featured conflicting ideas about how the Greens can win over disillusioned voters — and a very public clash of personalities.  

In one radio debate, Ramsay couldn’t even bring himself to say whether he liked his colleague. An influx of Polanski backers to the party represented a “hostile takeover,” one party member told the Guardian.

After so many tumultuous months, activists and members warned, now is the moment for party bosses to pull together.  

“I think the immediate priority for the new leadership group will be to focus on reforming a winning team for the important local elections in England and Wales in May 2026,” said one Green Party activist, granted anonymity to speak candidly. 

Countering Reform’s electoral threat on the right, while positioning themselves as a distinct force next to the fledgling left-wing party being formed by former Labour leader Jeremy Corbyn and MP Zarah Sultana, are puzzles Polanski must now solve. 

“I think Adrian is concerned about the potential direction Zack would take the party,” said a second Green Party activist, who worked on Ramsay and Chowns’ campaign. 

“We really don’t want to see a split between the parliamentary Green Party and the extra-parliamentary Green Party, that would make no sense at all,” they added. “I don’t think anyone is really hoping that that’s the outcome of this. I’m pretty sure the party will pull together.”

What a difference a year makes  

It was all very different just 12 months ago. Cheerful Greens quadrupled the number of their MPs to four in the 2024 general election, their most successful result ever. “The mood is entirely jubilant,” Polanski told POLITICO at last fall’s party conference. 

But by this summer, the leadership contest had plunged the party into a bitter internal battle. Ramsay and Chowns — who snatched their seats from the right-wing Conservatives in 2024 — promised to use their platform at the heart of Westminster to further develop the voter base the Greens had started to build at that election.

Doubling down on a proven electoral strategy for clinching seats, the pair argued, was key to winning more. That strategy is “building on the lessons that we’ve learned in recent years about how to appeal to a wide enough range of the population of the voters in a given area so that we can win their trust and win their vote at election time,” Chowns said in an interview for POLITICO’s Westminster Insider ahead of Tuesday’s result.  

Polanski — deputy leader since 2022 — instead promised a radical shift in how the party pitches for people’s votes in the first place.

He pledged to hammer the government on welfare cuts and its response to the war in Gaza. “My message to Labour is very clear,” he said. “We are not here to be disappointed by you. We are not here to be concerned by you. We’re here to replace you.”

“[Zack] thinks that we’re not articulating our case eloquently enough for people. He thinks we’re not reaching out beyond the existing Green core, and he has a strong case to make that the party needs to be a bearer of much more radical messaging about what Green Party politics and policy stands for,” said Jonathan Porritt, who co-chaired the party in its foundational years. “I’m not at all discomforted by that.”  

Polanski’s backers insist this brand of storytelling is essential for getting the Greens’ message across.

“Zack … doesn’t just think we should go out and about being angry, it’s more about how we recognize this moment and how people are feeling really let down and really out in the cold,” said Zoë Garbett, a Green member of the London Assembly alongside Polanski.

“[Zack’s] way of listening, storytelling and connecting with people I think is incredibly important because I think that’s where we failed as a party,” she added.  

Threats from right and left  

Polanski’s strategy includes offering a more forthright voice on the left to counter the rise of Farage’s insurgent Reform UK, which has tapped into voter disenchantment with mainstream politics.

Targeting younger left-wing voters who are fed up with Labour policy on Gaza and the cost of living will meanwhile leave Polanski competing directly with Corbyn and Sultana’s nascent outfit — and recent polling shows Green support from those voters crumbling when given that choice.

Polanski has left the door open to working with the new party.  

“I want to work with anyone who believes in the same values and policies that the Green Party do. What that exactly looks like it’s far too soon to say, because they [Corbyn’s party] don’t even exist yet,” he said Tuesday afternoon.  

There are “red lines” for Polanski, including if controversial former Labour MP-turned-pro-Gaza firebrand George Galloway is involved.

Chowns and Ramsay, by contrast, have urged the party to maintain a “distinctive identity.” Other members want preconditions laid down for any deal on the left.  

Green Party members “absolutely do want us to be a strong counter to Reform,” said the second party activist quoted above. “In terms of whether the best way to do that is to be something very similar to the new party set up by Corbyn and Sultana — I think there is a very, very big question mark over that.” 

The first party activist said a commitment to net zero and electoral reform should set the terms for any cooperation. “Whether the new Corbyn-Sultana party can commit to any Green Party terms is yet to be seen,” they argued.  

Meanwhile, Polanski has vividly ruled out working with Starmer. One U.K. government official said the new-look Green Party could end up pushing Labour to be bolder on its climate pledges. 

The new boss is meanwhile gearing up for the fight. 

“What [the victory] says to me is people have had enough of the politics of the right and the center-right for far too long, and actually really want to see these alternatives on the left,” Polanski said.  

Additional reporting by Charlie Cooper.