Zack Polanski has vowed to stay on as Green Party leader after his by-election defeat, as he faced pressure from within his own party to resign.
The leader of the Jewish Greens, Vivien Lichtenstein, said on Friday he should resign, adding it was a "big mistake" for him to have dodged a debate about a party conference motion that declared Zionism a form of racism.
Lichtenstein's comments come after former Green Party leader Caroline Lucas accused Polanski of failing to show leadership over the Zionism row.
Polanski, who came second to Labour overnight in the Holborn and St Pancras by-election, told BBC Breakfast he would "absolutely" stay on as leader and "of course" had not questioned that.
The Greens had hoped to take the seat, previously held by former Prime Minister Sir Keir Starmer, after a by-election success earlier this year.
Polanski lost out in Thursday's contest in London to Labour candidate Sagal Abdi-Wali, who secured 45% of the vote to his 33% - but the Green vote share was up by 22% on the 2024 general election.
In her comments calling on Polanski to resign, Lichtenstein told Times Radio: "I don't know which Jewish members of the party he's been working with – it certainly hasn't been with the Jewish Greens committee."
Her criticisms were similar to those of former Green Party leader Caroline Lucas who said Polanski should have attended the vote on the conference motion on Sunday.
The motion, which was passed by rank-and-file members to become official party policy, defined Zionism as an ideology supporting "an ethnonationalist Jewish state" and backed a "single democratic Palestinian state in all of historic Palestine", which includes modern-day Israel.
Lucas described the motion as "dangerous" and "flawed from top to bottom".
Polanski defended his absence from the controversial motion vote in Brighton, saying he was busy campaigning in the North London constituency.
Asked if he would resign, he said: "Of course I can carry on as leader of the Green Party."
He added: "Yes, I've taken a loss tonight but our movement is so much bigger than one election or one motion."
Having not answered questions about the Zionism vote for most of this week, Polanski confirmed in interviews on Friday that he would not have voted for the "imperfect" motion without it being amended.
However, he said "the displacement and genocide of the Palestinian people is clearly underpinned by a racist ideology".
Several UN reports have accused the Israeli government of committing war crimes which amount to genocide in Gaza. Israel has repeatedly denied all such allegations.
On Friday morning, following the Zionism row, Polanski was asked repeatedly on BBC Radio 4's Today programme whether he believes Israel has a right to exist.
"I don't believe any state has the right to oppress or to commit apartheid and certainly not genocide on another people," he said, adding: "I don't believe that's a state that anyone should be supporting."
Asked by presenter Nick Robinson for a "yes/no" answer on this question, he said: "I've repeated many times that I want to see equal rights for Israelis and Palestinians - at the moment Palestinians don't have equal rights so I think I'm answering your question really clearly."
But given his popularity among the grassroots, he may be safe from a leadership challenge in the near future.
Jonathan Bartley, the Green co-leader from 2016 to 2021, called on Polanski to "put his hands up" and "say sorry" - but did not demand he quit.
"I think [the vote] was a failure of leadership from Zack and there is a certain toxicity now from the Green Party," he told BBC Radio 4's World at One.
Bartley said the Green brand "needs to be detoxified", adding the party had seen an influx in members that have "maybe come from the left of the Labour Party, maybe from [Jeremy Corbyn's] Your Party" but "we're losing some older voters".
The Green leader has faced days of pressure over the Zionism motion. Four of the five Green MPs and one of the party's two deputy leaders opposed it, the Green deputy in Wales and some councillors resigned, while some local members and the European Green Party have distanced themselves from it.
Prime Minister Andy Burnham has called on Polanski to reverse the "completely wrong" motion.
Meanwhile, Labour chair Bridget Phillipson drew comparisons between her party's previous antisemitism scandal, telling BBC Breakfast she felt the Greens now face a "serious problem" with antisemitism.
Polanski has said anti-Zionism and antisemitism are distinct from each other and said nobody will be excluded from the party on the basis of their faith, place of worship or religious body.
