The educationalist who became the public face of sweeping school reforms in America - including the firing of hundreds of “incompetent teachers” - has resigned.

In just three years in charge of state schools in Washington DC, Michelle Rhee closed dozens of schools and developed a reputation for sacking teachers, including the head of her own child’s school.

But now, following a slump in her popularity and the loss of an election by her political sponsor, she has gone.

Her plans to clamp down on poor teaching in America’s lowest-performing state attracted both support from parents and opprobrium from the powerful teaching unions.

But her reforms, which saw her fire 165 teachers who failed to meet the required standard in a hated performance-assessment scheme, eventually proved too brutal for many, despite her achievement in raising test results.

A further 737 teachers were found to be “minimally effective” under the new Impact scheme and were given a year to improve their teaching or face dismissal.

“A not-insignificant number of folks will be moved out of the system for poor performance,” she said shortly after the sackings in July.

Ms Rhee’s resignation comes immediately after she was hailed a “warrior woman of our time” by TV host and social campaigner Oprah Winfrey.

At the time, Ms Rhee was promoting a new documentary Waiting for Superman, which claims powerful teaching unions are holding back education in America by making teachers virtually unsackable.

A recent BBC Panorama programme levelled the same criticism at the English education system, claiming that employment regulation and strong unions meant it was very difficult to oust poor teachers.

The Washington Teachers’ Union, which has welcomed Michelle Rhee’s resignation, criticised her reforms for going “too far, too fast” and said they failed to support teachers.

Ms Rhee was appointed to oversee Washington’s public (state) schools in 2007, promising to turn around their fortunes. The following year she was pictured in a classroom holding a broom on the cover of Time magazine. Before she took up her post, performance-related sackings were rare. But in her first year she sacked 79 teachers for poor performance, and a further 96 followed soon after.

After hiring 500 new staff at the beginning of the last academic year, she axed 266 teachers, citing budget cuts, although unions claim that this was a cover to get rid of older teachers.

The Washington unions have approved a new contract which raises teachers’ salaries by 21.6 per cent, but means pay is more strongly linked to classroom performance. It includes bonuses of #163;20,000-30,000 for teachers meeting certain benchmarks.

The change has made Washington teachers among the highest paid in the country. Education Secretary Michael Gove is expected to have his eye firmly fixed on the US as school authorities start to introduce performance-related pay schemes so they can apply for grants under President Obama’s Race to the Top initiative.

Mr Gove, who earlier this year said he wanted to make it easier to sack poor teachers, has also promised to create a more flexible pay structure to enable schools to attract and retain good teachers.

However, US academics have recently warned that bonuses based on pupil performance do not improve performance.

Research carried out on 300 maths teachers in Nashville, Tennessee, found that incentives of #163;3,000-9,000 did not raise classroom performance above the levels of teachers who were not offered the extra cash.

Chris Keates, general secretary of teaching union the NASUWT, told The TES when the research was published: “People see the idea of payment by results as unfair. It doesn’t take into account the variable intakes in the schools and is counterproductive to teamwork.”

Michelle Rhee

You’re fired - hundreds of you

Michelle Rhee was appointed in 2007 to oversee public (state) schools in Washington, a district that employs an estimated 4,000 teachers.

In her first 12 months in post she sacked 79 teachers for poor performance. After hiring 500 new staff at the beginning of the last academic year, she fired 266 teachers, citing budget cuts. In July, she sacked 165 teachers and 737 were registered as “minimally effective”.

Teachers in DC are to receive a new pay package. Potential salaries are to jump by 21.6 per cent, but pay will be more strongly based on performance.