Prime Minister Sir Keir Starmer phoned Iran’s President Masoud Pezeshkian and told him not to attack Israel and that regional war in the Middle East was “not in anyone’s interest” last night.

A Downing Street spokesperson said: “The Prime Minister said that he was deeply concerned by the situation in the region and called on all parties to de-escalate and avoid further regional confrontation.

“There was a serious risk of miscalculation and now was the time for calm and careful consideration, the Prime Minister said.

“He called on Iran to refrain from attacking Israel, adding that war was not in anyone’s interests.

“The Prime Minister underlined his commitment to an immediate ceasefire, the release of all hostages and increasing humanitarian aid to Gaza. He added the focus should be on diplomatic negotiations, to achieve those outcomes.”

Starmer and Pezeshkian’s conversation, their first since the Labour leader assumed office, came amid a wider diplomatic push to stop Iran from attacking Israel.

Also yesterday, a statement from the Prime Minister and the leaders of the United States, France, Germany, and Italy aimed at deterring Iran.

It said: “We expressed our support for the defence of Israel against Iranian aggression and against attacks by Iran-backed terrorist groups. We called on Iran to stand down its ongoing threats of a military attack against Israel and discussed the serious consequences for regional security should such an attack take place.”

Israeli officials say they expect an attack from Iran in the coming days in response to the killing of senior Hezbollah official Fuad Shukr in Beirut and the assassination of Hamas leader Ismail Haniyeh in Tehran (for which Israel has not claimed responsibility) in late July.

The leaders also expressed their “full support for ongoing efforts to de-escalate tensions and reach a ceasefire and hostage release deal in Gaza.”