A former spy who plays the drums to relax and once blamed “guy issues” for undermining Israel’s war effort in Lebanon, Tzipi Livni has emerged as perhaps the greatest threat to the tenuous grip on power of the Israeli Prime Minister, Ehud Olmert.

The scathing findings of the Winograd Commission, an Israeli Government inquiry that recently blamed Mr Olmert for the failings of last summer’s war, has set the stage for a struggle between the two leaders. And while Mr Olmert seems likely to cling to power for the time being, Ms Livni appears determined eventually to take his place.

Ms Livni’s closest friends, family and colleagues say that Israel’s popular Foreign Minister is convinced that she will be the next prime minister. “She knows she is the right person for this job,” said Dror Gal, a lawyer and confidant.

If Ms Livni succeeds, it would make the 48-year-old married mother-of-two Israel’s first female prime minister since Golda Meir resigned in 1974.

Ms Livni made her political ambitions known in the wake of the Winograd panel’s findings. In a controversial statement this month, she said that Mr Olmert should resign and declared herself as a candidate to replace him as head of their centrist Kadima Party and as prime minister.

But her political gamble appeared to backfire. Instead of defecting, Mr Olmert’s Kadima colleagues closed ranks around him, fearing that a leadership change would trigger a snap election in which the party was likely to lose support to the right-wing Likud Party, which leads in the polls. Critics accused Ms Livni of hypocrisy for holding on to her own parliamentary seat while asking Mr Olmert to step down.

“Livni proved that she was a good candidate for the chair of women’s organisations, at best,” the columnist Ben Caspit wrote the next day in Maariv, the Israeli daily. Aluf Benn, a leading Israeli columnist for the newspaper Haaretz, wrote that she came across “as an opportunistic and spineless politician who sold out just to keep her seat in power”.

But in a Government riddled with allegations of corruption, sex-scandal and fraud Ms Livni remains Israel’s most trusted politician, according to surveys. Recent polls show that between 65 and 68 per cent of Israelis want Mr Olmert to resign, and many moderate Israelis consider Ms Livni a potential next prime minister.

“She’s seen as disciplined, determined and intelligent — the opposite of other Israeli leaders,” said Yaron Ezrahi, a professor of political science at Hebrew University in Jerusalem. Time magazine selected her this year as one of the world’s 100 most influential people — a list that did not include Mr Olmert. The US Secretary of State, Condoleezza Rice, wrote for the magazine that Ms Livni’s strength was “a testament to her character”.

Before entering politics, Ms Livni worked for Mossad, Israel’s spy agency, and was a successful real estate lawyer. She joined the Knesset as a member of the Likud Party eight years ago.

When Ariel Sharon left Likud to form Kadima, he handpicked her to go along, giving her the third most powerful job in government. She quickly became his most trusted ally, helping him to broker the controversial Israeli pullout of the Gaza Strip in 2005. When Mr Sharon fell into a coma in January last year, Mr Olmert took over and promoted Ms Livni as his deputy and Foreign Minister, where she has won admiration for her diplomatic skills on the world stage. Now she is aiming for the top job.

“She’s spent many hours thinking of what to do and how to do it. It’s only a matter of time,” Mr Gal said.

For now, Ms Livni and Mr Olmert have an uncomfortable truce. She has agreed to serve in his Government, in spite of her concerns over his leadership. He has agreed not to dismiss her in spite of her betrayal. If she manages to convince her Kadima colleagues to elect her as leader, her main opposition for the prime minister’s job would probably come from her old party, Likud, led by Binyamin Netanyahu, whose popularity is at an all-time high.

Analysts here say that she could also face other obstacles: Israeli politics is dominated by men with extensive military backgrounds. However, Ms Livni hopes to turn this to her advantage. “Sometimes there are guy issues,” she said in an interview this year on the nature of Israeli politics.

Asked if there had been a “guy problem” in the handling of the Lebanon war, she replied: “Not only in the war. In all kinds of discussions,

“I hear arguments between generals and admirals and such and I say: ‘Guys, stop it’,” she said.

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