President Shimon Peres expressed his views on an Israeli strike against Iran in public “only when he felt there was nothing else he could do and we were close to the moment of truth”, insisted presidential aides.

An interview by Mr Peres last week in which the president openly opposed a unilateral attack by Israel on Iran’s nuclear installations has opened up a rift at the highest level of Israeli leadership.

In the interview with Channel Two, which was originally scheduled to coincide with his 89th birthday, Mr Peres said: “It’s clear to us that we can’t do it alone. We can only delay Iran’s progress. Thus it’s clear to us that we need to go together with America.” These words directly contradicted the views expressed by Prime Minister Benjamin Netanyahu and Defence Minister Ehud Barak that Israel has the capability to attack and seriously damage Iran’s nuclear programme and that it should do so if the US does not act soon.

The president also seemed to be criticising Mr Netanyahu in another interview when he asked how Israel’s first prime minister, David Ben-Gurion, would have responded to the Iranian threat.

While Mr Netanyahu has said that Ben-Gurion would have attacked Iran despite America’s position, Mr Peres said Ben Gurion “prevented war and withdrew from Sinai. He wanted to open the Straits of Tiran by force in 1955, but the cabinet decided against it.”

This was a major departure for a twice former prime minister who, in the past, has been a bitter political rival of Mr Netanyahu but since being elected has been very careful not to openly disagree with him. According to one of his advisers: “He simply felt now he had no choice, that there are moments when you have to do something for the good of the nation.”

Mr Peres, who has been one of the architects of Israel’s defence policies since the early 1950s, has been working in the past few years behind the scenes, counselling and supporting senior defence chiefs who are against an Israeli strike on Iran.

The president fears that not only could an Israeli attack lead to wide retaliation from Iran and its proxies but that its implications could significantly damage Israel’s strategic ties with the US. The Prime Minister has not responded publicly but his aides have briefed the press against the president, with one of them accusing him of responsibility for the deaths of more than 1,000 Israelis in terror attacks following the Oslo Accords.