The latest YouGov poll, conducted on 19–20 October, shows the UK Green Party achieving its highest-ever result, with 15 percent support if a general election were held today.
The populist right-wing Reform UK continues to lead with 26 percent, followed by the ruling Labour Party at 20 percent and the Conservatives at 17 percent. The Greens are now tied with the Liberal Democrats at 15 per cent – the latter currently hold 76 seats in Parliament, while the Greens hold only four.
The result marks a significant milestone for the party and reflects a sharp rise in its popularity since Zack Polanski was elected leader a month ago with 85 percent of the vote.
His election has boosted the Greens’ visibility across political and media circles, as the party announced that its official membership had grown by 80 percent since Polanski took office.
The Greens now claim more than 140,000 dues-paying members, surpassing the Conservatives, making them the UK's third-largest party by membership after Labour and Reform UK. The surge since Polanski's election reportedly exceeds the entire current membership of the Liberal Democrats, the party with which he began his political career.
Media spotlight and bold messaging
Membership soared further this week after a series of high-profile media appearances by Polanski, including a BBC interview on Sunday in which he defended his party's proposed wealth tax as a measure to "address deep inequality in our society" that could generate "between £15 and £25 billion a year".
The Greens were the first major UK party to officially describe Israel's assault as a genocide, calling for an immediate halt to arms sales and intelligence sharing with Israel.
In his BBC interview with Victoria Derbyshire, Polanski said the Gaza war had exposed "a failed neoliberal system" and reiterated that governments must "stop selling weapons to Israel".
He vowed that his party would "never stay silent about the mass slaughter in Palestine", linking the party's social and economic agenda to its position on Gaza.
He has also framed the Greens as "the only progressive alternative", rejecting "culture wars that distract from real economic issues".
Openly gay and Jewish, Polanski often says his personal experience fuels his solidarity with minority communities, including migrants. At his party conference, he argued that "the real danger from migrants comes from those arriving on private jets, not those arriving on small boats".
Labour's left drifts toward the Greens
There are signs of a shift among Labour's left toward the Greens amid growing frustration with party leader Keir Starmer.
Two Labour councillors from Swindon, Tom Butcher and Ribi Begum, defected to the Greens this month, following another colleague who made the same move last week. Both said they would serve as Greens until their terms end in May 2026.
"Our values and beliefs haven't changed," they said in a joint statement. "Sadly, Labour has moved away from them. When elected on a promise of fairness and equality, it’s important to represent those values through a party that truly upholds them."
Rising influence and growing scrutiny
The New Statesman magazine described the Greens as having transformed from a marginal force into "Britain's third major party", now representing the aspirations of many young voters.
Guardian columnist Owen Jones attributed the surge to the party’s improved media strategy and social media presence, as well as its focus on economic injustice rather than anti-migrant rhetoric - a narrative, he said, that both the right and Labour have adopted.
But right-leaning outlets have begun warning of what they call "the Polanski phenomenon".
The Times editorial board said the Greens' platform "poses serious risks and must be taken seriously,” calling Polanski inexperienced and his economic policies “unrealistic, with excessive taxation and spending".
Meanwhile, Bloomberg columnist Rosa Prince compared Polanski to "Britain's own Zohran Mamdani", warning that his populist rhetoric against the rich and political elites "lacks a coherent programme or clear vision beyond slogans".
She argued that his reliance on charisma and social media "comes at the expense of the environmental focus that should be central to any Green party".