What drove the UK Green Party to label Zionism as racism?

Delegates passed a binding policy resolution formally committing the party to backing a single democratic state across historic Palestine and demanding that Britain halt arms sales to Israel, voting 1,022 in favor to 813 against.

Citing the Palestinian casualty count in Gaza as the primary rationale, deputy leader Mothin Ali defended the measure by arguing that The motion defines Zionism quite clearly. It defines it as an ethnonationalist movement. It defines it as ethnic cleansing. It defines it as genocide.

The policy triggered immediate backlash from British Jewish communal groups, with the Movement for Progressive Judaism condemning the decision and declaring that The Green Party has made antisemitism party policy and become a racist party.