As part of a Government overhaul of league tables parents will be given the opportunity to compare schools based on the amount of progress made by the top pupils in all secondary schools between the ages of 11 and 16.

The new league table figures, out next week, are expected to show that up to a third of pupils in state schools are gaining worse results in English and mathematics exams at 16 than in comparable tests taken at the age of 11. The changes to league tables come at a time when there are concerns that too many schools prioritise "borderline" pupils on the cusp of scoring a C grade to inflate their headline results at the expense of the brightest or those struggling the most, The Telegraph reports.

Schools Minister Nick Gibb has claimed that league tables have evolved over the past 20 years. "They encourage a degree of 'gaming' by some weaker schools, desperate to keep their school above the standard that would trigger intervention by Ofsted [the regulator] or the Department for Education" says Nick Gibb.

"Some teachers are entering pupils for qualifications that are more in the interests of a school's league table position than the child's own prospects. If you look at the GCSE results since 1997 you see a dramatic increase in the proportion of C grades being awarded. Weaker secondary schools have been given an incentive to focus only on these pupils. But what about the B students, who might, with better teaching, achieve an A? Or the E students who could get a D?"

The Government will release results for more than 4,000 state funded and independent schools in England, which will show just 86,209 out of 567,170 (almost one in six) pupils in state schools finished compulsory education with A* to C grades in a range of traditional subjects: English, maths, science, languages and either history or geography.

Government results will also disclose that the number of children being entered for separate GCSE exams in these five disciplines dropped in the state system last summer from 21.8 per cent to 21.6 per cent.

In addition, school by school data will strip out "equivalent" courses such as BTECs, which are offered as an alternative to GCSEs and were added to official rankings under Labour. It will enable parents to assess school GCSE performance with and without equivalent exams.

Brian Lightman, General Secretary of the Association of School and College Leaders (ASCL), insisted "[schools are] not forcing anyone to take specific GCSEs but the existence of league tables has put them under immense pressure".

"Our view is that there are some courses in which the [GCSE] equivalence level has been overly generous but we would be concerned about any blanket statement from the Government that says any course worth more than one GCSE is automatically bad."

If you would like to read more about league tables click on the links below:

• No evidence schools are falling behind says research
• Teachers feel there is a 'lack of trust in their abilities'
• GCSE students forced to 'play the system', says exam board

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