A popular primary school which rides high in league tables has "serious weaknesses", according to the Government watchdog Ofsted.

Wibsey Primary in North Road is the largest primary school in Bradford with 693 children on roll.

Its results are better than many Bradford primary schools - in the 2002 league table Wibsey was ranked 58th out of 159 for scores achieved by 11-year-olds in SATs.

But Ofsted has criticised the quality of teaching, which has been "allowed to drift", leadership and management.

While children are mostly achieving "appropriate" standards and are well-behaved and cared for, inspectors found there was "too much unsatisfactory teaching, and less good and better teaching than is now found in most other schools".

Out of 72 lessons observed in July's inspection, 15 per cent were below par and the report describes teaching as "unsatisfactory" overall, for all age groups. "Serious weaknesses" is the next category up from a failing school and means Wibsey now faces more rigorous monitoring.

The verdict came as a shock to staff and parents, who praised standards of the school's teaching in Ofsted's questionnaires.

Head teacher Ian Williamson said: "We were very disappointed with the inspection team's findings, but we accept the report and are determined to resolve the issues it raises within the shortest possible time frame.

"This is a school which has maintained standards through an LEA reorganisation, a significant expansion in numbers and a major building programme. Wibsey continues to be a place where the children are provided with a caring environment in which to learn."

Strengths of the school identified in the report are the provision for children with special needs, good behaviour and relationships, and the way pupils' learning is enriched through well-chosen and planned visits, including residential stays.

But attendance has been allowed to deteriorate. The report said: "The number of holidays taken by pupils in school time is not monitored, inspection of records indicated a significant number had taken well in excess of ten days, all of which had been authorised by the school."

While school leaders coped well with the turbulent school reorganisation and building work, they are criticised for placing "insufficient emphasis on raising standards and improving quality": governors have not been effective enough as a 'critical friend' to the school.

Ofsted's verdict brings to 22 the number of Bradford district schools in Special Measures or with serious weaknesses.