A former head of Israel’s Mossad intelligence agency, Efraim Halevy, is predicting a “dramatic” improvement in relations with the US if the prime minister Benjamin Netanyahu is defeated in elections today.

Ties between the two allies have been strained, especially since Mr Netanyahu addressed the US Congress on 3 March against the wishes of the Obama administration, about the perceived threat to Israel and the world that would ensue from an agreement between Tehran and a group of major powers over Iran’s nuclear programme.

Mr Halevy is among a string of former intelligence chiefs to come out against Mr Netanyahu during the election campaign, foremost among them Meir Dagan, Mossad chief under Ariel Sharon, who was the keynote speaker at an opposition rally.

Israel’s next PM: Herzog's rival candidates Show all 4 1 /4 Israel’s next PM: Herzog's rival candidates Israel’s next PM: Herzog's rival candidates Benjamin Netanyahu Seeking a fourth term, the 65-year-old has made security a main issue. His policy of settlement-building on occupied land has put him at loggerheads with many of Israel’s traditional allies. But he is still seen as the person most likely to cobble together a coalition on the right. AFP/Getty Images Israel’s next PM: Herzog's rival candidates Tzipi Livni Sacked by Mr Netanyahu in December after cabinet infighting, Ms Livni, a centrist who served as Justice Minister and chief peace negotiator, seemed destined for the political wilderness until she struck the partnership deal with Isaac Herzog. A leading advocate of a two-state solution with the Palestinians, the 56-year-old has pledged to seek ways to resume peace talks. AFP/Getty Images Israel’s next PM: Herzog's rival candidates Yair Lapid Mr Lapid, 51, was the rising star of Israeli politics in the 2013 election. His centrist Yesh Atid party came second behind Mr Netanyahu’s Likud. As a result, Mr Netanyahu appointed him Finance Minister. Fired amid the government squabbling in December, Mr Lapid is a potential kingmaker, predicted to win 12 seats. AFP/Getty Images Israel’s next PM: Herzog's rival candidates Ayman Odeh The Arab Israeli lawyer heads the Joint Arab List and is gaining momentum. It is the first time Israel’s four Arab parties have united and they are predicted to win around 13 seats. Mr Odeh, 40, from Haifa, advocates an Arab-Jewish “alliance of the disadvantaged”. He has said his party would not join any government. AFP/Getty Images

“I think the atmosphere will change dramatically and Israel and the US will be able to return to the state they were in in the past,” Mr Halevy told The Independent. “In the past, the way we conducted our affairs was not confrontational but rather by seeking to find common ground on common issues on which we should co-operate and dealing with the differences behind closed doors and not up front.

“Differences over Iran might persist,” he added. “It’s not a foregone conclusion that a new government in Israel will take a totally different position on the Iranian negotiations. It could be that even the new government will find there are a lot of holes in the agreement that are undesirable. But if this is the case, the method it will be dealt with is quiet negotiation and quiet dialogue with the United States and not confrontational steps to alienate one part of the hierarchy in the US as opposed to the other.”