She is already being spoken of as an Israeli leader in waiting. Today the Israeli Foreign Minister Tzipi Livni brings to London the campaign to destabilise the incoming Hamas Palestinian government by starving it of cash.
Israel's policy - described by a spokesman as putting "the Palestinians on a diet, but not to make them die of hunger" - has left London feeling squeamish. Tony Blair and Jack Straw will today undoubtedly show solidarity with Israel, saying Britain is not in the business of funding terrorists. But in private there is anguish that the policy will bring malnutrition to innocent Palestinians and punish them for taking part in a democratic election. The Palestinians are completely dependent on foreign aid for their survival and Israel's campaign to put 3.6 million people on starvation rations is foreboding.
The EU announced on Monday that it would provide €120m (£85m) in emergency assistance to prevent financial collapse, but has kept silent on what it will do once Hamas takes office. Britain is encouraging the EU to pay salaries directly and bypass Hamas.
Ms Livni's hardline views were displayed earlier this week when she said that the Palestinian President Mahmoud Abbas was "irrelevant" and could not be permitted to become "a fig leaf for a terrorist entity".
US policy is to prop up Mr Abbas at all costs and Israel's interim ruler Ehud Olmert quickly stepped in to clarify Ms Livni's remarks, saying he hoped the Palestinian President would stay in office.
Ms Livni, 47, has made a considerable political journey from her early support for a Greater Israel to realisation that the country cannot remain a democracy while occupying Palestinian lands and ruling over a population that despises it. A teenager born to a nationalist family, she was nearly arrested for violently protesting against Henry Kissinger's ill-fated shuttle diplomacy. Despite her closely held dream of a Greater Israel, she maintains that she has long been a centrist on the national question. Raised in a hardline Likud household, Ms Livni has an ideological pedigree that is hard to top.
"My family is part of the founding history of Israel," she has said. Her father's gravestone bears the inscription, "Here lies the head of operations of the Irgun" - refering to a pre-independence military organisation set up to fight the British and the Arabs. The stone also bears a carved map of Greater Israel extending to the opposite side of the Jordan river.
A former Mossad officer, Ms Livni is the daughter of Zionists - classified as terrorists by the British authorities. Her father, Eitan, was the Irgun's head of operations when it blew up the King David hotel in Jerusalem in 1946, killing 28 Britons, 41 Arabs, 17 Jews and five others. The subsequent wave of terror attacks he led outraged British public opinion, leading the government to abandon the Palestinian Mandate and turn the problem over to the UN, with disastrous consequences for the Palestinians.
Ms Livni was one of Sharon's favourite colleagues - part of the kitchen cabinet that planned the unilateral withdrawal from Gaza last year and his key emissary. She was also the first person he asked to join the centrist party Kadima after breaking away from Likud during a row with the right over the withdrawal.
Ms Livni rose to become a lieutenant in Israel's army before joining its foreign spy agency Mossad when she was 22. During her time at the agency it was involved in a failed assassination attempt on the Black September leader Abu Daoud. In 1981, her first year as a foreign spy, Mossad arranged the destruction of a nuclear reactor Saddam Hussein was building at Osirak.