Christine Gilbert, the next chief inspector, is a workaholic and shopaholic who has yet to lose all the habits she acquired in 18 years as a history teacher and head.

Colleagues describe her as inspiring. As the chief executive of Tower Hamlets in east London, she is credited with helping schools improve GCSE results in England’s poorest borough.

When she joined the borough in 1997, 27 per cent of pupils gained five or more A*-Cs. Last year the proportion rose to almost half.

At Tower Hamlets, Ms Gilbert picked up a reputation for quickly reading and then returning colleagues’ work covered in corrections scrawled in red ink.

Her first taste of media attention as chief inspector came as her appointment to the pound;150,000-a-year post was announced.

As Ms Gilbert’s husband, Tony McNulty, is a Home Office minister, political opponents suggested cronyism, generating such headlines as “Anger as minister’s wife gets top schools job” and “A case of jobs for the girls?”

Her closeness to Whitehall was also suggested earlier this year when Ruth Kelly, former education secretary, chose her to head a government review of personalised learning.

But claims of favouritism were dismissed by colleagues in local government and by teachers’ leaders, who are impressed by Ms Gilbert’s CV. She got the chief inspector’s job after stints as director of education in Harrow as well as Tower Hamlets, and has shown her willingness to assert her independence from the Government.

John Bangs, National Union of Teachers’ head of education, described attacks on her as disgraceful. “She has run an incredibly tight ship in Tower Hamlets,” he said, pointing out that although the borough is Labour-controlled, it does not have a city academy.

Christine Whatford, former chief education officer at Hammersmith and Fulham, who has known Ms Gilbert for 30 years, agreed. She said: “I can’t think of anybody who is less defined by what their partner does. She is completely her own person.”

As a secondary head, Ms Gilbert, 55, has first-hand experience of turning around a school.

Mary Bousted, general secretary of the Association of Teachers and Lecturers, worked with Ms Gilbert in the 1980s when she was deputy head of Bentley Wood girls’ school in Harrow, north-west London, and then moved to join her when Ms Gilbert became head at nearby Whitmore high.

Ms Bousted said: “Christine Gilbert is an outstanding appointment. She was one of the most powerful influences on my teaching. When she was appointed at Whitmore, it was struggling and in danger of sinking. Within three years, it was one of the most popular schools in Harrow.”

At Whitmore, Ms Gilbert integrated a unit for pupils with special educational needs, including learning and behavioural difficulties, into the school so successfully that it received regular visits from policy-makers and other heads.

But not all her moves were in keeping with New Labour orthodoxy. As head of English, Ms Bousted was permitted to reintroduce mixed-ability teaching.

“Personally, she was a good laugh and very human, but I remember she could be quite scary if she wasn’t convinced you were doing the right thing. But once you convinced her, you got her full support,” she said.

And six years ago, when Tower Hamlets received an excellent Ofsted report, just 20 months after being judged to have serious weaknesses, Ms Gilbert said: “This raises questions about the appropriateness of wholesale privatisation as the automatic response to problems in LEAs.”

Alasdair Macdonald, head of Morpeth school in Tower Hamlets, said: “She is very focused and very demanding. She sets high standards for herself and others but is very supportive in helping you meet them.

“She is one of the hardest workers I have met. If we have a meeting with Bengali parents at 5pm on a Sunday, she’ll be there if she thinks it’s going to help.”

Amid such plaudits, there is one endorsement Ms Gilbert could probably have done without. Chris Woodhead, former chief inspector, praised her “solid job” in Tower Hamlets and said she deserved her new post.

But Ms Bousted and other union leaders are hopeful she will avoid Mr Woodhead’s example and instead follow in the footsteps of David Bell by being willing to criticise the Government, yet being broadly supportive of its overall standards agenda.

Certainly, any failure is unlikely to be down to lack of hard work.

Colleagues describe Ms Gilbert as driven, and say she is known for staying late in the office, regularly working until 10pm.

It is something of a relief, then, to find this hard-working high-flier has been known to misbehave, indeed to truant. A friend reports how Ms Gilbert, always impeccably turned out, has been known to leave boring conferences to indulge in her favourite pastime - clothes shopping.

* jon.slater@tes.co.uk