At a primary school in Lewisham, south London, a remarkable scene unfolded on a dreary Saturday morning. Over 600 Green Party activists streamed in from across London and beyond, converging in what organisers declared the largest turnout in the party's history for a non-general election event. This gathering, focused on council campaigns months away from ballots, underscores a profound shift in British politics, where the default choice for left-wing voters is no longer Labour.
A Hinge Moment in British Politics
The winter of 2025-2026 represents a pivotal hinge moment, as disillusionment with the Labour Party fuels a surge in support for alternatives. In Wales, Plaid Cymru benefits; in Scotland, the SNP; and in many English cities, including inner London, the Greens are gaining ground. This transformation is starkly evident in Lewisham, a borough once dominated by Labour, which swept every council seat and the mayoralty in 2022.
From Near-Shutdown to Rapid Growth
Just a year prior, the local Green Party in Lewisham had shrunk so drastically it neared closure. However, by early 2025, membership stood at around 500, and by autumn, nearly as many were signing up weekly. By the start of 2026, membership soared to approximately 2,500, rivalling the Green stronghold of Hackney. Ed, a volunteer tasked with welcoming new members, noted that his solo efforts in January had expanded to a team of nearly 25, reflecting the party's explosive growth.
Harriet Lamb, the Green Party CEO, expressed astonishment at the turnout, sipping tea in the heaving school hall. She remarked, "Six months ago, I wouldn't have believed we could fight Lewisham. Now I look across Manchester, Birmingham, Newcastle and I think: this is a social movement." This sentiment echoes a broader trend, as the Greens transition from a fringe entity to a mainstream political force.
The Role of Leadership and Local Issues
While Westminster observers often attribute the Green surge to the energetic and media-savvy leadership of Zack Polanski, activists and voters in Lewisham tell a different story. Praise for Polanski flows freely, but the primary driver of their shift is condemnation of Labour. Many cite specific grievances, such as Labour's stance on Gaza, with non-white voters uniformly naming Palestine as a key reason for abandoning the party.
Local issues also play a critical role. Residents express concerns over Labour council policies, such as approving large housing developments with minimal social rent units, or implementing facial recognition technology that raises safety fears among black communities. One resident, a black man, stated, "As a black man, I don't feel safe," highlighting a deep sense of disconnect from Labour's values.
A Gift and a Challenge for Polanski
For Zack Polanski, this surge presents both an opportunity and a potential headache. He leads a party that must now scale its infrastructure to support rapid growth, with members warning of sustainability issues. As one campaigner noted, "We have an infrastructure for a party of 50,000 members when we'll soon be at 200,000. It's not sustainable." Polanski acknowledges these challenges, comparing the Greens to a startup that must "run and catch the ball at the same time."
Despite the pressures, Polanski remains focused on policy development, engaging with figures like Nobel laureate Joseph Stiglitz to craft platforms on tax and inequality. However, the demands of leadership are immense, with constant media attention and activist expectations, as seen in Gorton where he wore five lapel mics simultaneously.
Looking Ahead: A New Political Landscape
The optimism among Green activists is tempered by caution, as many are embarking on a second political marriage after disillusionment with Corbyn's Labour. One prospective councillor warned against "building a project around just one guy," emphasising the need for broader structural support. Yet, the energy at the Lewisham event, where Polanski addressed a packed hall with wide-eyed amazement, signals a transformative moment.
As British politics evolves, the Green surge in Lewisham exemplifies a wider realignment, driven by voter disenchantment with Labour over moral and local issues. This shift not only redefines the left-wing landscape but also poses significant challenges for a party navigating rapid growth and heightened expectations.
