Jewish Greens' leader has said Polanski should resign in the wake of a Zionism row and by-election defeat.

The Green leader faces pressure over his response to a party motion declaring Zionism a form of racism, as well as his by-election loss.

Labour's Sagal Abdi-Wali beats Green Party leader Zack Polanski to hold the north London seat.

The prime minister has intervened in the row over the motion passed by members at Green Party conference.