Benjamin Netanyahu, the leader of the right-of-centre Likud party, has been asked to form Israel’s next government.

Mr Netanyahu said Israel faced “great challenges” including the global economic crisis and what he said was Iran’s wish to obtain nuclear weapons.

He said he would try to form a unity government with his political rivals.

But Tzipi Livni, leader of the centrist Kadima, has suggested she would rather be in opposition than join a government led by Mr Netanyahu.

Kadima narrowly defeated Likud in the election held on 10 February, but Mr Netanyahu has the support of religious and right-wing parties in the Israeli parliament.

His position was bolstered on Thursday when Avigdor Lieberman, head of Yisrael Beiteinu, which favours tightening the Israeli blockade on Gaza, said it wanted him to be prime minister.

Let’s unite to secure the future of the State of Israel
Benjamin Netanyahu
Likud leader

Profile: Benjamin Netanyahu

President Shimon Peres and Mr Netanyahu held a news conference to officially announce that the Likud leader now has six weeks to put together a coalition.

He told the news conference he wanted to open talks with his political rivals to form a “broad national unity government for the good of the people and the state”.

He said: “I call on Kadima chairwoman Tzipi Livni and Labour Party chairman Ehud Barak and I say to them - let’s unite to secure the future of the State of Israel.”

On Iran, Mr Netanyahu returned to a key campaign theme, suggesting that Tehran had emerged as Israel’s greatest security threat.

The Islamic Republic was seeking to develop nuclear weapons, he said, as well as sponsoring the Hezbollah and Hamas militant groups in Lebanon and Gaza.