Britain's Greens have voted, shamefully, to say Zionism is racism

It is a damning moment for a political party with pretensions to power

E year the Green Party briefly polled at 21%, ahead of both the Conservatives and Labour, as part of a four-way split. Since Andy Burnham became prime minister, the party has lost about half its support. At their conference this weekend the Greens voted to define Zionism as racism. The party thereby deserves to fade back into irrelevance.

As well as calling Zionism racist, the new policy urges the destruction of Israel. Jews can instead live as full citizens in a Palestinian state if they choose. It endorses Palestinian violence and demands the release of "prisoners of conscience".

Many of the party's Jewish members feel persecuted. Almost all British synagogues support the idea that Jews should have a state. Freedom of worship is a fundamental right, but they fear that their devotion will lead to them being branded racist.

Greens for Palestine justify their position with the claim that Jews are colonists, like whites in South Africa or the pieds-noirs in Algeria. That makes Palestinians freedom fighters. They argue that no state should be set up on the basis of ethnicity. Jews should not feel persecuted, they say. The party's Jewish members cannot be punished for their beliefs, including Zionism.

This new policy was born partly out of anger at the plight of the Palestinians. Israel's government has treated the people of Gaza with merciless and unrelenting violence. Israeli settlers, sometimes motivated by hatred of Palestinians, are daily using force against Palestinians on the West Bank, often with the connivance of the army.

However, Greens for Palestine, who prepared this policy, have got their history upside down. Far from being colonial, Zionism began as a liberation movement, like the Polish or Czech nationalism that emerged in the 19th century under the Austro-Hungarian empire. The pioneers did not look to London or Paris, as white South Africans or Algerians originally did. Instead, Zionists claimed that Jews needed a homeland where they could be safe from pogroms -- a belief later tragically borne out not only in the second world war, but also among Jews who fled Arab countries after 1948.

The Greens are equally wrong about today. To blame all Israelis -- all Zionists, indeed -- for atrocities against Palestinians and to seek to punish them as a group is unjust. The Greens' new policy only entrenches the divisions tearing apart Palestine. To say Israeli Jews can opt to live under a Palestinian government, possibly run by the murderers of Hamas, is to give them no choice at all.

In Britain how can Green members of Parliament serve their "racist" synagogue-going constituents? Will staffers look kindly on Jewish Greens accused of harbouring a racist ideology? The pro-Palestine activists who insisted on this motion are unlikely to tolerate either. Instead, this new policy will give succour to thoughtless antisemitism, which is already widespread on the far left and hard right.

It is depressing that planet-loving Greens, who support things like eating lentils and planting trees, have faint-heartedly indulged the hard left. Their leader, Zack Polanski (pictured), who is Jewish, has tried to accommodate it. He needs to grasp that his movement has been taken over by zealots.

These zealots express no real criticism of Putinists or Kim Jong Un or the Chinese Communist Party, let alone misgivings about Middle Eastern conflicts in Syria, Sudan or Yemen. But they have an unquenchable desire to denounce Zionists. You don't think that might have something to do with hating Jews?

Instead of wringing their hands, the old Greens should seize back their party or leave it. Worshipping in a synagogue is not tainted by racism. From this moment, voting Green is. ■