Campion School, in Bugbrooke, was issued with a Notice to Improve by the Government education watchdog after it found students were making inadequate progress in English, maths and science, despite an outstanding sixth-form provision.

The report states: "Significant improvement is required in relation to students' achievement, especially in English.

"The main school provides an acceptable standard of education, but students make inadequate progress in years seven to 11 in English, and in mathematics and science the progress they make is significantly less than similar students make in similar schools."

Inspectors said although the quality of teaching was satisfactory overall, there was some inconsistency.

"While there are examples of some rigorous marking, some books seen during the inspection had not been marked recently; some had not been marked since September.

"The result is that some books contain uncorrected work, do not guide students on how to improve, and some students are not taken to task about large amounts of incomplete or scrappy work."

Campion School received more than 661 applications for its 232 places for year seven entry this September.

The report said in 2007 the school missed its relatively unchallenging target for the percentage of students achieving five or more A*-C grades at GCSE by a wide margin.

Inspectors acknowledged staff were keeping a close eye on the students' progress and the school was working effectively to support youngsters who are at risk of leaving without qualifications.

The report also commented on the school's specialist status having a positive impact on enriching the curriculum and supporting the teaching of modern languages in local primary schools.

Praise was given to headteacher, Bob Clayton, for having a good knowledge of the school's strengths and weaknesses. Parents commented positively on his influence.

Mr Clayton said: "This was not a surprise and I was aware of the issues before my appointment 16 months ago. I have been working with the governors and staff to address what has been highlighted.

"I am totally confident that in a year's time Campion will be out of the Notice to Improve."