A groundbreaking scheme to give teachers’ unions responsibility for turning around failing schools could double in size, after it produced dramatic improvements.

Two years ago Chicago Teachers Union was handed sweeping new powers in 10 chronically underperforming schools. Last week city officials met to discuss extending the “partnership” programme to a further eight to 10 schools.

Marc Wigler, partnership initiative coordinator at the union, said six of the eight primary schools showed an average 75 per cent gain in reading comprehension test scores in 2003-4, the scheme’s first year. Two secondaries taking part reported modest improvement, although two primary schools continued to languish.

“For the most part, it seems to be working,” said Chicago public schools spokesman Peter Cunningham. “We’re willing to consider extending it.”

The programme represents a radical departure from customary intervention strategies at failing US schools, which have looked to outside parties such as education management firms or private consultants, or handed direct control to the education authority.

Chicago’s scheme is led by teachers. In a vote taken before its inception, 80 per cent of staff had to be on board before schools could sign up.

Teachers then chose a remedial instruction curriculum, specially designed to boost reading among at-risk students, from a pre-approved list. Union officials check up on individual school’s progress every other week. The schools received roughly $200,000 (pound;111,000) a year each. Most implemented Success For All, a programme to boost attainment that includes one-to-one coaching and intensive testing.

Harnessing existing teachers to boost performance at struggling schools has often been resisted because they have been viewed as part of the problem.

But Mr Cunningham said: “You can’t automatically assume the problem lies with the teachers. Sometimes they’re the only ones holding things together.”

Fred Metz, principal at Medill elementary, an inner-city school, said Chicago’s scheme meant all-important staff “buy-in” - they chose the way to improve rather than having reforms imposed.

At his school, where most children live below the poverty line, the number of pupils hitting national reading targets more than doubled to 20.5 per cent under the scheme last year.

David Plank, director of the education policy centre at Michigan State university, said: “Trying to do reform without the active engagement of teachers is (doomed).”

Mr Cunningham said union takeover was just one of the options under Chicago’s Renaissance 2010 initiative, which aims to farm out school management to employers, community groups and other partners.