Dramatic declines in top GCSE and A-level results at private schools across England this summer have led to accusations they ‘played’ the system last year when teachers awarded grades.

Official figures show the proportion of Years 7 to 9 GCSEs in private schools fell from 61.2% last year to 53% this year, when pupils had to sit exams – a fall of 8 .2 percentage points.

The difference was three times larger than that of the overall studies, which saw a drop of 2.7 percentage points, from 26% last year to 23.3% this year.

The pattern repeated itself with A-levels, where private schools saw a more dramatic drop in A*/A grades than other school types following the reintroduction of public examinations after three years. The proportion of A*/A entries in private schools has fallen from 70% in 2021 to 58% this summer. In high schools, A*/A grades have gone from 57% to 50%.

In some private high schools and sixth form colleges, where up to 90% of results were given A* by teachers last summer, grade level has fallen by 25 to 30 percentage points.

Robert Halfon, the Tory chair of the education select committee, said this year’s results showed the private sector had “treated the system for all it’s worth” during the pandemic.

“These differences show how vital reviews are. The decision to try to eliminate grade inflation and protect the timeliness of these qualifications is the right one. We need to get back to the integrity of the 2019 grade profiles. It seems the independent sector has exploited the school-rated grades system for all it was worth. That’s why Ofqual’s plan to control grade inflation is the right one.

In order to avoid exposing the inflation in grades last year, some schools that would typically make student success public are keeping their full results secret. The Head Teachers’ Conference (HMC), which represents major independent schools, has advised its members against publishing the results of the whole cohort to ‘avoid unnecessary comparisons between GCSE and A-level results Has this year and previous years, which have either used different assessment methods or different standards”.

Critics said schools that manipulated the system under teacher-rated grades widened the academic achievement gap between working-class students and those from more affluent backgrounds. They accused the government of leaving soaring grades in some schools unchecked last year. This summer, Ofqual set national exam pass marks to curb the inflation of marks towards 2019 levels.

Bridget Phillipson, Labour’s shadow education secretary, said: ‘Some private schools are playing with the system and there is no transparency. Labor called for an investigation into last year’s ratings, but ministers were happy to let inequality grow.

“It is essential that all pupils are on an equal footing, but the Conservatives have presided over a yawning achievement gap between pupils in public and private schools, which has increased since 2019. Labor would end tax breaks for private schools to fund a brilliant public education. for each child. »

An analysis of the A-level results by Education Datalab concluded that the claim that private schools had “rigged” the results was “a bit harsh”. He said that while the absolute difference in A*/A grade percentages in 2022 compared to 2021 showed one of the biggest declines at independent schools in relative terms, privately educated students were around 20 % more likely to receive an A/A* in 2021 than in 2022, but the same is true for students in academies, comprehensive schools and modern high schools.

Barnaby Lenon, chairman of the Independent Schools Council, said: ‘Last year’s teacher-assessed grades have undergone rigorous quality checks. Review boards found no evidence to suggest that any type of school or college was more likely to have provided grades that did not reflect their students’ level of work.

The HMC declined to comment.