Chris Woodhead, chief inspector of schools, said up to 4,000 schools may be “coasting” with reputations for good results, while their pupils could do better.

Under the new arrangements, operating from 2000, there will be a measure to determine which schools are coasting. They will be identified by inspectors and required to produce action plans.

The new inspection system will also introduce “light touch” inspections for successful schools. Around 30 per cent of schools with high test and exam results will have a less intensive scrutiny.

Mr Woodhead said at a launch of the consultation paper that weak schools’ problems must be brought out into the open.

The inspection burden on effective schools is likely to be reduced by 25 to 60 per cent. The paper says: “It may be that in the smallest primary schools, no more than three inspection days are needed, compared with five at present. ” For secondary schools with 60 or more teachers, the number of days may be reduced from 50 to 13.

Mr Woodhead said that schools deemed effective are likely to be those in the top 25 to 30 per cent in curriculum tests and GCSEs in English, maths and science.

Schools will only get between four and eight weeks’ notice of their inspection, compared with the current two terms. The chief inspector said he believed it was time to move beyond the frenetic activity by schools in the months before inspection that had been “an index of immaturity”.