Every Christmas Jacqui Smith, the new Home Secretary, organises a Scaletrix race for friends and family near her Redditch constituency. She is particularly delighted if she wins but failing that she wills on her husband or two sons.

Friends tell that story to demonstrate her sense of competitiveness: that her mild-mannered style belies a steely determination even when playing.

Her appointment to Home Secretary, one of the three most important jobs in the Prime Minister's gift, was a surprise. She entered the cabinet as chief whip only last year, and while she was expected to be promoted was not expected to leap frog her colleagues to land such a plum job.

She has emerged from the whip's office with her reputation enhanced, no mean feat. Colleagues, some of whom usually hate chief whips, say she has no enemies, a unique state of affairs in the parliamentary jungle.

Ms Smith is a rare ministerial animal, widely credited with speaking "fluent human". The 44-year-old entered Parliament in 1997 and reached ministerial office in 2001. By 2003 she moved into the Department of Trade and Industry where, as Minister for Women, she brought in civil partnerships legislation, and in 2005 she was appointed Schools Minister.

She wore her Blairite credentials on her sleeve but has nevertheless impressed Mr Brown with her ability and down to earth style.

After John Reid, Charles Clarke and David Blunkett, three political bruisers, Ms Smith's style is bound to be welcomed in the Home Office. But the scale of her challenge cannot be over-estimated. One of the most important tasks will be to gain a fresh hearing for anti-terror legislation and length of detention without trial which Tony Blair failed to get through but which Gordon Brown intends to revisit.

She is not afraid to speak her mind, and people who know her well insist she will not be a push over. They think her manner will go down well with police officers, immigration officials and the terrorist specialists, all of whom she will have to deal with regularly.

With a majority of only 2716, she now has a marginal seat so between her family, her ministerial responsibilities and nursing her constituency she has little time for outside pursuits although she gallantly cites the theatre and football as interests.