If the tactics for raising standards were applied sector-wide, says Terry Melia, chief inspector for the Further Education Funding Council: “About 35,000 students each year would be getting one or more extra A-levels.”

Inspectors found “remarkable” improvements in performance at Winstanley Sixth-form College, Wigan. Its overall pass rates have risen from 74 per cent to 87 per cent in four years. But the most dramatic leap - from 76 to 87 per cent -came in just two years, following a range of initiatives to monitor and raise standards.

Dennis Lavelle, the Wigancollege’s principal, said: “If they want a 95 per cent pass rate, we can do it by chucking them out in the lower sixth, but we don’t want to do that. We don’t want to be selective.”

There is, however, a tough quality control system, he says. Early monitoring ensures that people get on the right courses with a back-up for students to switch mid-stream if they are causing concern. Everything is monitored, as senior staff including Mr Lavelle visit lessons regularly to ensure the quality of teaching is up to standard.

“We go in and in and in until they have got it right,” he said. There is also very close personal tutoring. But the most innovative scheme is the staff assessment regime.

“Our quality assurance system is tough. Students name teachers and grade them on a whole body of things including the frequency of homework setting and marking. It’s tough for the staff, but when we are having staff reviews we can talk about specifics, not generalities.”

Senior management is also open to the same scrutiny from staff, who complete questionnaires which go to the chair of governors. “I think we have very professional staff as a result,” he said.

While some credit for improvement must go to neighbouring schools - GCSE grades have improved during the same period - the college should take most of the credit, said Dr Melia.

The quality of A-level intake over that time appears to have remained pretty constant, and the college serves an area of Wigan which is fairly deprived economically.

Winstanley came in the top 10 per cent of colleges in last year’s Government performance league tables. Not only has its pass rate shot up but students’ average grades have risen, too. At least 50 per cent achieved an A or B in music, physics and Spanish.

While slightly below the national average in economics, English, philosophy and religion, many students had completed their courses in one year, partly as a result of the chance to switch courses mid-stream. Students on new vocational courses are also performing above average.

In a report on the college this week, the inspectors give nine grade ones out of 14 areas of management and the curriculum observed.