The sacking of Harriet Harman from her job as Social Security Secretary was the biggest surprise of Tony Blair's first reshuffle.

In many ways Harriet Harman, 47, sums up everything that is New Labour.

She is intelligent, she looks good on TV, her instincts are to protect the middle-classes and she is married to a moderate union leader - the T&G's Jack Dromey.

But she can also infuriate Old Labour stalwarts simply by getting out of bed and she has a tendency to become a bit flaky under pressure.

'Accident waiting to happen'

Harriet Harman in happier days

For years, Labour's spin doctors have insisted "Hattie" must be on the front bench because she presents the right image to the voters.

And for almost as many years her detractors have insisted she is an accident waiting to happen.

That prediction appeared to come true in 1996 when she decided to send her son to a selective school - a move which flew in the face of official Labour policy.

Her opponents, including deputy leader John Prescott, were apoplectic and immediately demanded her sacking from the shadow cabinet.

It was one of Tony Blair's most difficult periods as leader before the election.

But he stood by her - partly out of loyalty and partly because he was sending his own children to a grant maintained school.

But the resentment never really subsided and there is always a well of support on the Labour backbenches for anything anti-Harman.

From left-winger to moderniser

She started her political life as a left-winger, working for the National Council for Civil Liberties and demanding "extra parliamentary activity" to further her causes.

She won Southwark in 1982 and never looked back, allying herself to the, as-then unnamed, modernisers.

Tony Blair has always supported her and made her his Social Security Secretary after the election.

But even then there were signs of potential trouble ahead when he made free-thinking Frank Field her deputy, charged with the task of reshaping the welfare state.

Many believed he was the secretary of state-in-waiting and it was only Labour's backtracking or radical measures that spiked his guns.

But Ms Harman appeared to stumble from one crisis to another, most dramatically over the plans to cut single parent benefits which landed the government with its biggest backbench revolt earlier this year.

It was a row that would have been hard enough for the most skillful front bencher to defuse - and she failed.