Campbell says too little about Thatcher's mother or her elder sister, but he leaves lasting impressions of a diligent, serious girl who divided her time between lots of homework, church and helping out in the shop downstairs, with little time for friends.

Thatcher later sanctified her father for instilling in her conservative self-reliance, thrift, Churchillian patriotism and hard work, but Campbell debunks her hagiography. When she went to Somerville College, Oxford, at 18 in 1943 'and embarked upon her own career she quickly adopted a style of life and political values a world away from his spartan ethic', he writes. Workaholic Thatcher's 'mum and housewife' image is also repeatedly challenged. Campbell's research counters many myths. She wasn't as tough as she projected, he says. As education minister in the 1970s she cut free milk for pupils, but also saved the Open University. She proved decisive in the Gulf and Falklands wars and called for swifter action in Bosnia, but she U-turned on issues such as global warming and defence, often to please the Americans. She encouraged private enterprise and also borrowing, and left much of the country reliant on banks, divided and in debt, the author writes.

Campbell writes dispassionately about a leader who is still loved or loathed, and succinctly explains why those emotions and much of her political and economic legacy still lingers in Britain, but his neutrality is hardly holiday reading. When the 1986 Westland affair surfaces on page 369, readers must still plough through 140 more pages for the poll tax and the end.

The author's study of Hong Kong is brief. He ticks the boxes for the 1984 Joint Declaration but omits Thatcher's stumble on the steps of the Great Hall of the People. He describes how she devoted more time to British interests in Hong Kong after she lost power in November 1990 and, with the blessing of her successor John Major - whom she scorned - handled 'the charmless prime minister Li Peng' with 'a skilful mixture of outspokenness and tact' in March 1995, and then attended the handover. Campbell shows the rise of future governor Chris Patten, but makes no reference to Thatcher's alleged nickname for the Legislative Council, the 'Hong Kong County Council'.

The Iron Lady is a cautionary tale of hard work undone by hubris, and the account of Thatcher's tearful ousting will be required reading for dragon ladies and their underlings. The abridgement provides new insights in every chapter but is unlikely to alter contemporary opinions about her legacy. Her impression is still too vivid, and Streep has a tough act to follow.