Britain’s Green Party’s resolution Saturday declaring that Zionism is racism and calling for one Palestinian state from the river to the sea with Jerusalem as its capital ignited intense backlash across the political spectrum, with Israel’s Foreign Ministry barring Zack Polanski, the Greens’ Jewish leader, from entry into Israel.

The Greens’ former deputy leader expressed his dismay over the vote, saying that the party has become openly antisemitic.

The Green Party has now become “the U.K.’s first openly antisemitic party,” he said, adding, “Make no mistake: This motion removes the right of the state of Israel to exist. It requires it.”

“This new party policy has made it impossible for the Greens to be an acceptable coalition partner in any future government make-up,” an Australian outlet called The Australian declared.

“I am deeply saddened the ‘Zionism is Racism’ motion has passed. It doesn’t reflect Green principles or my own view. The Green Party has long supported the principle of self-determination, and I stand by our 2024 manifesto commitment of equal rights of Israelis and Palestinians,” wrote Adrian Ramsey, one of the Green Party’s MPs, on X.

“Zionism isn’t racism — the Green Party is,” wrote The Jewish Chronicle, a British Jewish newspaper.

The Board of Deputies of British Jews posted, “The motion passed by the Green Party today is an attack on the Jewish community. It is an antisemitic platform, based on a grossly offensive distortion and erasure of Jewish experience and identity.”

Israel’s Foreign Ministry blasted the Green Party’s resolution in a statement on X, accusing the political party of aligning itself with Hamas ideology.

“Today, the Green Party in Britain ceased to act as a political party and became a body that gives legitimacy to terrorism. The Greens have adopted not only the green of Hamas, but also its ideology: the elimination of the State of Israel through armed struggle,” the Foreign Ministry said.

“The shocking resolution adopted today legitimises armed struggle, calls for a Palestinian state ‘from the river to the sea’ — meaning the destruction of the State of Israel — and labels as ‘racist’ the aspiration of the Jewish people for self-determination,” the ministry added, saying, “This goes far beyond the boundaries of legitimate political debate. As long as this resolution remains in place, it will be a stain on the history of the United Kingdom.”

“Every political party in Britain, first and foremost the governing Labour Party, must unequivocally reject this twisted resolution,” it concluded.

In a second statement, the Foreign Ministry took aim again at the resolution, adding that Israel’s Foreign Minister Gideon Sa’ar had banned Polanski from Israel.

“The resolution constitutes a clear antisemitic text according to the IHRA definition, as it denies the Jewish people’s right to self-determination,” the ministry tweeted. “Therefore, as a first step, Foreign Minister Gideon Sa’ar has decided this evening to declare Green Party leader Zack Polanski barred from entering Israel. The decision has been coordinated with the relevant authorities.”