The UK Green Party has experienced significant ideological shifts in recent years, with growing concerns about antisemitism, Islamist influence, and political opportunism under the leadership of Zack Polanski, according to Shahrar Ali, the party’s former deputy leader. Ali, who served in various roles within the Greens for nearly two decades, voiced his apprehensions about the party’s direction in an interview, warning that its changing stance extends beyond internal party politics and poses risks to British society.

Ali highlighted an acceleration of these trends since Polanski, who is Jewish, assumed leadership in autumn 2025. He described the party’s transformation as a departure from its traditional values, marked by an “authoritarian drift” and a growing radicalism that has unsettled longtime members and some MPs, including figures such as Caroline Lucas, Adrian Ramsay, and Ellie Chowns.

A key factor in the Greens’ shift, Ali suggested, is the rapid expansion of its membership base over the past year without adequate vetting of newcomers’ political views. He attributed the influx to an increase in pro-Palestine activists and former Labour Party supporters associated with Jeremy Corbyn, some of whom were reportedly expelled from Labour amid antisemitism allegations. Ali argues that this has contributed to a rise in both overt and covert antisemitic sentiments within the party.

The former deputy leader pointed to the party’s electoral strategy as evidence, noting the Green Party’s first parliamentary by-election victory earlier this year in Gorton and Denton, which he said was achieved with significant support from Muslim voters and heavily focused on Gaza-related messaging. Ali expressed concern that the party’s campaigning on Palestinian issues frequently overlooks or minimizes the suffering of Israelis and Jewish communities, particularly in light of recent violence since October 7.

Ali also raised the issue of Islamist influence within the Greens, asserting that the party is straying from its historically secular and environmentally focused identity. He cited Deputy Leader Mothin Ali as exemplifying a reluctance to critique Islamist elements or Islam itself, signaling a shift toward privileging Muslim perspectives at the expense of broader secular values. This dynamic, Ali believes, is contributing to a divide where the party both actively seeks to attract Muslim voters while alienating others.

Polanski’s stance on Israel has also drawn scrutiny. When asked by the media whether he believes Israel has a right to exist, Polanski declined to provide a direct answer. Ali contrasted this with the treatment he received for opposing the party’s controversial “Zionism is racism” motion, including suspensions and disciplinary action, while more explicit calls for the dismantling of Israel within the party have gone unpunished.

Though the Greens failed to capture the Holborn and St. Pancras by-election seat in October, they made gains compared with previous elections. Ali suggested the party faces a precarious future, as traditional Green voters might withdraw support in reaction to the party’s current trajectory, while younger cosmopolitan activists and students may continue to back its Gaza-focused platform.

Questions remain about the representativeness of recent party decisions. Ali noted that only about 1% of the membership participated in the vote on the “Zionism is racism” motion, leaving open the possibility that the wider membership might hold a different position. Nonetheless, he warned that the activist core is influential and capable of shaping broader membership outcomes.

Regarding the recent vocal opposition from senior Greens, Ali expressed skepticism about the timing of their critiques, suggesting they emerged more as political calculations after electoral setbacks rather than as principled stands against extremism or antisemitism within the party.

Overall, Ali cautioned that the Green Party’s shift under Polanski signals a deepening ideological fracture, one that he contends threatens the party’s integrity and carries wider implications for British political and social cohesion.