The Green Party has adopted a motion declaring Zionism a form of racism, because nothing says "broad tent" quite like passing a resolution that makes a significant chunk of your membership feel like the tent is on fire. The motion, put forward by activists at the party's conference in Brighton, passed by 1,022 votes to 813, exposing tensions between the party's newly enlarged membership base under leader Zack Polanski and its MPs elected at the last general election.

Polanski, who is Jewish, did not take part in Sunday's vote, and four of the party's five MPs opposed it. In his first comments since the motion passed - having declined interviews on Monday, presumably hoping the news cycle might just move on - Polanski released a lengthy statement saying he "take[s] seriously my responsibility to make sure everyone feels safe and welcome in our party." He added: "As leader I will not accept any exclusion, or refusal to engage with anyone, because of the religious or communal body they are part of." He also said "antisemitism and criticism of the Israeli state are, and must always be, completely distinct," which is a sentence that would be less necessary to say if the motion hadn't just blurred that exact line.

The motion defines Zionism as an ideology supporting "an ethnonationalist Jewish state" and backs a "single democratic Palestinian state in all of historic Palestine." It states: "The real, material, manifestation of Zionism has been the historic and ongoing dehumanisation, displacement, dispossession, disenfranchisement and destruction of Palestinians." Israel's foreign ministry responded by banning Polanski from entering the country, while some Jewish groups have described the motion as an "attack on the Jewish community." So that's going well.

The backlash has been swift and multi-pronged. More than a dozen Labour MPs reported the Greens to the equality watchdog on Monday, saying the motion raised "serious questions." Nine Labour MPs also referred the Green Party to Sussex Police, asking the force to investigate whether alleged "possible antisemitic offences" at the conference merit a criminal investigation. Sussex Police and the Green Party have been contacted for comment, presumably while someone in the Green press office quietly updates their CV.

On Monday, a group of Labour MPs - organised by former Home Office minister Mike Tapp - wrote two letters to the Equality and Human Rights Commission (EHRC) raising concerns about the motion, and amendments to protect Jewish members attending Zionist synagogues being voted down. "Taken together, these developments raise serious questions about whether Jewish members can participate freely and equally in the party, and whether their religious and communal connections could expose them to complaints or disciplinary action," their letter said. The EHRC, which previously found failings in how Labour handled antisemitism - so it's not like they're new to this particular rodeo - told the BBC it would "consider each complaint carefully" and had not at this stage launched an investigation. It added that political parties must comply with the Equality Act 2010 and "take steps to avoid discrimination," which is the legal equivalent of a parent saying "I'm not angry, I'm just disappointed."

The European Green Party, of which the Green Party for England and Wales is a member, released a statement on Monday saying it wanted to "unequivocally distance" itself from the motion. The umbrella body said it would "immediately demand clarity" from the party's leadership on how they would protect Jewish people and self-determination. Nothing says "family of parties" like a public distancing statement.

Meanwhile, Green MP Ellie Chowns told Radio 4's PM programme she was "deeply saddened" the motion had become party policy but disagreed it was antisemitic, saying it was underpinned by "principled opposition to the actions of the Israeli government." She suggested a review of Green policymaking processes was needed since "less than 1%" of the party's more than 200,000 members had participated in the vote. So to recap: a motion passed by less than 1% of members has now triggered police referrals, an EHRC complaint, a foreign government ban on the party leader, and an international Green distancing statement. Democracy is a beautiful, chaotic thing.