Around 300,000 fewer top GCSE grades could be awarded this week in a “shock” to pupils and their parents, it has been suggested.

Exams regulator Ofqual has said a return to pre-pandemic grading means this year’s national GCSE results in England will be lower than last year and similar to levels in 2019 – the year before coronavirus.

An education expert has predicted families may find the “substantial drop” in top GCSE grades awarded this summer “hard to accept”, and results day on Thursday “will not be as enjoyable” as during the pandemic years.

Professor Alan Smithers, director of the Centre for Education and Employment Research (CEER) at the University of Buckingham, has suggested there could be around 300,000 fewer entries graded 7 or above compared with 2022 if grading standards return to 2019 levels.

It comes after Covid-19 led to an increase in top GCSE grades in 2020 and 2021, with results based on teacher assessments instead of exams.

Prof Smithers said: “The restoration of the 2019 grade pattern in England will result in another record drop in top GCSE grades as the profligacy of teacher assessment is reversed.

“Although the changes as percentages may not look much, given the huge number of entries, they amount to a substantial drop of some 300,000 top grades.

“This will come as a shock to the pupils and their parents, who may find the grades that emerge hard to accept given what those in the classes above them had received in the preceding three years.”

But he added: “It is necessary because the emergency reliance on teacher assessment raised the number of top awards by 437,964, giving many pupils a false picture of their capabilities.

The return to exams in 2022 reduced the excess by 138,597, leaving more than double that distance to go.”

Last week, some 73,000 fewer top A-level grades were awarded in England, Wales and Northern Ireland than last year as part of efforts to bring results back down to pre-pandemic levels, exam boards said.

But there were around 32,000 more top grades awarded than in 2019.

Figures covering GCSE entries from students in England, Wales and Northern Ireland will be published by the Joint Council for Qualifications on Thursday.

While traditional A*-G grades are used in Northern Ireland and Wales, in England these have been replaced with a 9-1 system, where 9 is the highest.

A 4 is broadly equivalent to a C grade, and a 7 is broadly equivalent to an A.

In Wales and Northern Ireland, GCSE results are expected to return to pre-pandemic levels next year.

The report predicts that girls’ lead over boys in scoring more top GCSE grades could narrow this year, but female students will “still remain far ahead”.

Prof Smithers said: “The under-performance of boys in school examinations tends to be accepted, but it should be treated as a national concern since it indicates that boys are not developing their full potential.

“This is of national importance, because we are not developing the talents of half the population as fully as we could.

“This can only lead to a decline in the nation’s economic competitiveness and ultimately loss of its standing in the world.”

The English Baccalaureate (EBacc) – a Government measure – aims to make sure that pupils take English, maths, science, a humanities subject and a language at GCSE.

The Government’s aim is to see 90% of pupils in England studying the EBacc subject combination at GCSE by 2025.

But the report by CEER suggests “the poor take-up” of modern foreign languages has meant the Government is far off its target.

It said: “If the Government values learning languages, then it should set up an inquiry to clarifying why it is not happening as was hoped.”

Prof Smithers said: “Without radical change, the percentage achieving EBacc will never increase much beyond where it is now. The idea of establishing this particular set of core subjects appears to be beyond its sell by date.

“I suspect that the EBacc will be left to quietly fade away.”

In the analysis before GCSE results day, Prof Smithers highlighted the “intriguing” trend that religious studies is becoming more popular at GCSE.

He said: “Its popularity could be because the lessons are there, and the exam is there, and it looks like an easy win.

“Or it could be a consequence of the competition to get into the highly successful faith schools and the importance those schools attach to religious studies.

“Or it could be that pupils really do see it as an opportunity to grapple with life’s fundamental questions.”

An Ofqual spokesperson said: “This year is the second in the phased return to normal of national exams. This means we expect grades to be similar to those seen in 2019, the last year before the pandemic.

“Because of the disruption students have faced there are still grade protections in place which mean a student will be just as likely to achieve a particular grade this year as they would have been before the pandemic.”

A Department for Education spokesman said: “This year, GCSE grading is largely returning to normal in line with plans set out by Ofqual almost two years ago, to ensure qualifications maintain their value and students get the opportunities they deserve.

“For students collecting their results, those opportunities will be greater than ever before thanks to our brand new T-levels, alongside A-levels and other vocational and technical qualifications.

“We will also continue to support pupils through initiatives like the National Tutoring Programme, which is benefiting pupils most in need of support, including those in exam cohorts.”