One of the world’s leading Jewish philanthropists has warned that Israel risks losing its Jewish soul if it gives on the search for a two-state solution with the Palestinians.

Charles Bronfman, co-founder of the Birthright Israel tours for young Jews, said that even if peace were not immediately within reach, that was “no excuse for inaction,” in an op-ed for the American Jewish newspaper The Forward.

He called on American Jews to “vigorously support” a two-state solution as the only way to ensure Israel’s long-term future as a Jewish democratic state.

A single state encompassing Judea and Samaria (the West Bank) would over time either become no longer Jewish or no longer democratic, he said.

While a two-state solution was the “only outcome” acceptable to both Israelis and Palestinians, a unitary state would become “a prescription for prolonged civil war, he warned.

“The risk of being wrong and losing our Jewish soul is an existential threat in our time — a greater one than intermarriage.”

Mr Bronfman chairs the Israel Policy Forum, an American body which backs a two-state solution.

Only a few days ago, Israel’s influential Education Minister Naftali Bennett rejected the idea of two states.

He told the BBC World Service the Palestinians already had a state in Gaza and they had turned it into a “terror state”.

Ceding the West Bank to the Palestinians would be giving them a second state “and I vehemently oppose that”.

Mr Bennett instead suggested the Palestinians could have “less than a state” in which they governed themselves but would be denied an army in order not to pose a threat to Israel.

In 2010, Sir Mick Davis, the then chairman of the Jewish Leadership Council in the UK, sparked controversy when he warned of the danger of Israel retaining the West Bank. "If… the world community no longer believes that a two-state solution is possible, " he said, "we de facto become an apartheid state because we then have the majority who are going to be governed by the minority."