It is not exactly typical for a British party conference, let alone that of one of the smaller parties, to elicit international condemnation.

Yet that is the position the Green Party of England and Wales is in today after Israel's foreign ministry said it was banning their leader, Zack Polanski, from entering the country.

The cause was the motion proposed by party members and adopted by the conference on Sunday, declaring Zionism, which is the belief in the right to a Jewish homeland, to be racism.

The Green motion describes Zionism as an ideology supporting "an ethnonationalist Jewish state", and supports instead a "single democratic Palestinian state in all of historic Palestine".

It's hardly likely that Polanski or indeed many Greens are going to be much troubled by Israel's condemnation of the motion. One major factor in the Greens' electoral gains over the past year or so, a hugely successful period for the party, has been their clear and vocal condemnation of Israel's war in Gaza and actions in the region more generally.

What may be more troubling for the Greens institutionally is what this episode reveals about some of the dynamics in the party.

Many Greens are proud of the party's internal democracy: this motion was proposed by and voted on by party members. Yet that has resulted in the scenario of leading Green elected politicians facing scrutiny over party policy which the vast majority of them opposed.

Polanski, who is not an MP, wanted changes to the motion which were rejected by the conference, and ultimately did not participate in the debate or vote. Of the Greens' five MPs, four opposed the motion.

The most vocal of them was Adrian Ramsay, the MP for Waveney Valley, who was a Green co-leader for four years until September last year when he and his running mate were defeated by Polanski by a vast margin.

Polanski banned from Israel after party's motion declaring 'Zionism is racism'

Jewish Greens chair says she could leave party over 'Zionism is racism' motion

So an element of this is the changing nature of the Greens' activist base under Polanski's leadership, moving away from an environmental focus to a more general left-populist politics, incorporating a large element of 'anti-imperialist' foreign policy.

Yet this may not be the last issue where that results in a public dispute between the membership and their MPs, four of whom were elected at the last general election under different leadership.

And it is striking that, though Polanski's election as leader was a clear symbol of that shift in the Greens' approach, he did not back this motion. So this could presage tensions too between Polanski and the party membership, some of whom will have been inspired to join the Greens by his leadership.

In practical terms, the Green MPs will be able to continue espousing a different position in parliament to the party's new policy.

The Greens do not have a whipping system, meaning that MPs are free to vote as they wish. This is also true of their councillors, including in the almost 40 councils where the Greens are in power after the May local elections.

It will be interesting to see whether as a result of these tensions there is a push either to constrain the ability of the party conference to make policy, or in the other direction - to constrain the ability of elected representatives to defy party policy.

Separately, this motion may present a political headache down the line for Andy Burnham.

In his Labour conference speech last week, the prime minister said he was forming a "national commission" on electoral reform, with a view to changing the system used for general elections in the long-term.

While Burnham did not specify what system he wanted, he said that Labour would at the next general election commit to a new system where "everyone's vote counts and everyone's voice is heard".

Under a move to any more proportional system, on current trends, there would likely be more Green MPs as a result. In the scenario of a hung parliament, the Greens are a party to which Labour would naturally look for support as part of the progressive bloc.

And yet the Greens are also now a party whose actions this weekend have been condemned by the Labour chair, Bridget Phillipson, as "shameful" and "fundamentally wrong". Angela Rayner, the communities secretary, said the Zionism motion "crosses a line and is rightly being condemned across the political spectrum."

Labour has long been divided on the question of electoral reform. Their leader now has a clear position in favour but the Green motion this weekend could have the unintended effect of bolstering opposition within Labour to that element of the prime minister's agenda.

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