A more humane GCSE system should be introduced so teenagers are not stuck in a “demoralising” cycle of retakes when they do not achieve a “standard pass” in English or maths, a headteachers’ union has urged.

Geoff Barton, general secretary of the Association of School and College Leaders (ASCL), is calling for a new literacy and numeracy qualification to be developed that “does not represent a cliff-edge over which many must fall”.

His comments came as students in England, Wales and Northern Ireland will receive their GCSE results on Thursday, as well as results for many Level 2 vocational and technical qualifications (VTQs).

In England, many students who do not secure at least a grade 4 – which is considered a “standard pass” – in English and/or maths GCSE are required to retake the subjects during post-16 education.

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.

The number of pupils in England achieving at least a grade 4 in maths and English GCSE is expected to fall this year amid efforts to restore grading to similar levels to 2019 – the year before the coronavirus pandemic.

Mr Barton said the return to pre-pandemic grading this summer meant a return to “the forgotten third” – the proportion of young people who are left without a grade 4 in GCSE English and maths.

He said: “These young people then have to go through the grind of retaking these qualifications in post-16 education – where most again fall below the benchmark.

“It is incredibly demoralising and instead of building confidence in the vital skills of literacy and numeracy, it has precisely the opposite effect.

“We have to introduce a more humane qualification system in which this forgotten third is not accepted as some sort of necessary collateral damage.”

Students in England are currently funded to retake maths and/or English until they achieve a GCSE grade 9 to 4.

For students with a grade 2 or below, they can either study towards a pass in functional skills level 2 or towards a GCSE grade 9 to 4.

Mr Barton added: “The answer is to develop a new style of English and maths qualification which can be taken by pupils at the point of readiness, which builds confidence, and which does not represent a cliff-edge over which many must fall.”

ASCL has called on the Government to consider creating a “certificate of proficiency” in literacy and numeracy – a qualification which would be taken by all students when they are ready, not only at the age of 16.

The union envisages that many pupils would still take GCSEs in English and maths under the proposals, but these GCSEs would demonstrate “mastery in the discipline” rather than acting as a proxy for literacy and numeracy.

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 2019.

In Wales and Northern Ireland, GCSE results are not expected to return to pre-pandemic levels until next year.

A Department for Education spokesperson said: “We are returning to pre-pandemic grading this year, meaning results should be in line with 2019. It’s important for students that their qualifications hold value now and in the future, ensuring we have a system that treats students fairly compared to previous years.

“We remain committed to driving up standards as demonstrated by England’s continued rise up the international league tables in English and maths.

“This is so important as we know students who leave education with a good grasp of English and maths increase their chances of securing a job or going on to further study. This is why we support students who do not hold GCSE grade 4 or above in English and maths at age 16 to continue studying these subjects. We will also be driving up standards through the Prime Minister’s ambition for all students to study maths to 18.”

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.

In 2019, more than a third (35.4%) of state school students in England did not achieve grades 4 or above in English and maths GCSEs. This figure fell during the pandemic years.

Last year – when grades were set at a midpoint between 2021 and 2019 – the proportion of state school students in England who missed out stood at 31.2%.

Lee Elliot Major, professor of social mobility at the University of Exeter, called it a “national scandal” that many teenagers will miss out on a grade 4 or above in maths and English language GCSEs this summer.

“We need a long-term inquiry to investigate why successive governments have failed to address an issue that continues to plague the British education system,” he said.

Prof Elliot Major added that the worry for pupils is that one dropped grade in English and maths GCSEs “can mean missing out on a sixth-form place, damaging future life prospects”.

Professor Alan Smithers, director of the Centre for Education and Employment Research at the University of Buckingham, said it was “striking” how few students who resit their English and maths GCSEs actually pass second or third time around.

In his report, the expert said: “It must be soul destroying to continually have to retake exams that you have failed in, perhaps several times, and to be denied entry to apprenticeships and much else if you cannot pass them.

“Surely, there is an urgent need for a policy rethink.”

Ahead of GCSE results day on Thursday, the Liberal Democrats have warned that students in England are being let down as millions of lesson hours are being taught by non-specialist teachers.

An analysis by the Lib Dems claims to show that the average GCSE pupil will have had one in 10 lessons with a teacher who is not a specialist in that subject over the past two years.

Speaking on Tuesday, Education Secretary Gillian Keegan said GCSEs were “very important exams”.

She told Times Radio: “For me, they were very important because I didn’t do A-levels. They were the thing that got me on to my apprenticeship.

“For me because that was my step into the workplace, they were a game changer and I also didn’t think I was going to pass many and I ended up passing more than I thought.”