Zack Polanski has declared Britain’s two-party politics “dead and buried” as his Green party won its first ever mayoral election.

The Greens unseated Labour from mayoral power in the east London borough of Hackney after 24 years. The new mayor, Zoë Garbett, told reporters she was “elated” and promised it was just the beginning, after the party won with 35,720 votes to Labour’s 26,865.

“Across London and the country, people have made it clear that they are desperate for an alternative to this failing Labour government,” she said. “It’s not old politics … versus new parties. This is about a system of fear versus a movement of hope.”

“All the work I’ve ever done has been to change the system and services that let people down, harm people and widen inequality. Our borough has over a quarter of a million people,” added Garbett, who succeeds the Labour mayor Caroline Woodley.