The Green party leadership election – by far the highest-profile in the party’s history – has largely been seen through the traditional lens of left and centre. On the one hand is Zack Polanski, the deputy leader and London assembly member whose insurgent campaign has attracted a surge of former Corbynites to the party. He’s seen as the left candidate. The incumbent, Adrian Ramsay (no relation to me), and his new running-mate, Ellie Chowns – both rural MPs – have been described as eco-centrists.

While there is some truth to that, it’s not quite so simple: after all, Ramsay and Chowns, like Polanski, have called for a wealth tax and renationalisations, and have denounced Israeli genocide in Gaza. This is hardly Starmerite centrism. To think about the real distinction, it might be an idea to go to Lancaster in 2007.

At the time, the party was holding a tense annual conference that was split between two currents whose differences help make sense of what’s happening today. I was one of the “realos” (realists). We wore suits, hoping any passing journalist would take us seriously. The other side were known as the “fundis” (fundamentalists), and they seemed to have exaggerated their hippy garb. I remember two people in druid gowns – perhaps because of genuine pagan beliefs, but probably also because they were trolling us.

The realo v fundi terminology originated in disputes within the German Greens in the 1980s over whether to enter coalition governments. In the party in England and Wales, the stakes were lower: in 2007, we were holding a referendum on whether the party should have a leader, replacing the then system of having two “principal speakers”.

For realos, this change was a statement of intent: it was about becoming serious. For fundis, there was, as the realo Natalie Bennett, who joined in 2006, put it to me, “a great deal of concern that this would be a major change in the culture of the party”. We won the referendum, but the leadership role it produced is highly limited. The leader gets the title, a desk, a salary if they don’t have one, press office time and one vote on the party executive. They can advocate, but can’t change policy, choose spokespeople or direct strategy. And they’re easily replaced: elections are every two years.

Many older Greens remain queasy at the idea of a leader – certainly a “strong” leader. Both this queasiness and the limited power have shaped the party ever since, and meant that leadership contests have tended to focus on organisation-building strategy or presentational emphasis and style, not policy. In the first one, in 2008, the realo MEP Caroline Lucas and permanently besuited 26-year-old Norwich councillor Adrian Ramsay were elected leader and deputy virtually unopposed; they advocated that resources be focused on the two target constituencies in which they were the candidates – leading to Lucas becoming the first Green MP in 2010.

Afterwards, though, she was busy in Westminster, unable to tour the country building the party on the back of this progress and, despite the thriving anti-austerity movement, in which many of us were active, party membership stagnated.

Our generation of (then) Young Greens developed a broadly shared understanding that the party was held back by two main things: the perception that we were just about the environment (rather than a party for the millions of leftwing voters abandoned by New Labour); and a fear of conflict. I had a mantra: “Greens can either be controversial, or ignored. Too often, the party chooses the latter.”

In 2012, Lucas and Ramsay stood down, and Bennett won the election – largely because she presented a serious plan for membership growth. She toured the country and cheerfully adopted leftist language. In her first leader’s speech, she said: “Ask not what the trade unions can do for us. Ask what we can do for the trade unions.” By 2014, membership had more than doubled to almost 28,000. In 2015, it surged past 60,000 … until Jeremy Corbyn ran for Labour leader, and thousands left to join that project instead.

Many, though, didn’t leave, and the legacy of that membership surge remained, both in party income and in hundreds of activists getting themselves elected as councillors (a phenomenon the MP and 2018-2021 co-leader Siân Berry describes to me as “Natalie’s legacy”). Since the end of Corbynism, space has opened up again on the left, and this, combined with effective mobilisation of resources, led to hundreds more Green councillors and four MPs in 2024.

But the last year has felt stagnant. With Starmer lurching right, there’s an obvious space in British politics that the Greens are struggling to take. The average score in the past 10 polls for a Westminster election – about 11% – is better than ever. But sluggish compared with Reform UK.

In April, Adrian Ramsay was asked on BBC Radio 4’s Today programme whether he agreed with the party’s policy that “trans men are men, and trans women are women”, and failed to answer five times – triggering condemnation from the Young Greens. Two weeks later, his co-leader, Carla Denyer, announced that she wouldn’t seek re-election and, in May, Polanski launched an energetic campaign with the slogan “We need bold leadership. Now.”

Ramsay and Chowns’ campaign is, instead, focused on their parliamentary roles – being “in the room where it happens”. This seems to me a mistake: historically, Greens have thrived when the leader isn’t stuck in Westminster. For some longstanding members, Corbynites joining to “back Zack” is scary. Some fear Polanski’s mooted ecopopulism, worrying it will attract people who “aren’t really Green”. Much of this fear isn’t about policy difference, but culture. Older fundi-types who liked Corbyn’s socialism but feared that the movement behind his leadership was a “cult of personality” now have similar worries about Polanski. Chowns and Ramsay, on the other hand, exude the kind of gentle, conflict-averse, consensual leadership style that the fundis used to advocate (sitting uncomfortably with their hyper-realo insistence on the centrality of Westminster). In other words, the Green party division isn’t really so much about left and centre as it is about differing ideas about political power and how to wield it.

For me, Polanski takes the realo acceptance of the need for charismatic leadership and blends it with the fundis’ belief in extraparliamentary organising and social movements. His position – that the party should be bolder in articulating its positions, that it shouldn’t be embarrassed by opinions that the Daily Mail considers scandalous (but are shared with much of the population), that it should lead the left – isn’t a new, un-Green one. It’s one that our generation of members has been making for two decades. Indeed, it was the approach that delivered the vast membership surge in 2013-2015, which made the subsequent electoral successes possible. And it’s the approach that will be needed to stop the recent membership surge directing their energies to Zarah Sultana’s new project.

British politics is in a moment of flux. The two-party system is clearly breaking down. Huge numbers of people fundamentally distrust our whole system, and large numbers of seats, particularly left-leaning urban constituencies, are actively looking for a proudly progressive alternative to Labour. Polanski’s bolder platform offers Greens a chance to step up. I hope the party takes it.