Half a million teenagers are going to receive their GCSE results later today.

Grades are going to be based on teacher assessments, and a report has warned that some parents may call for the exams to be scrapped permanently if more top grades are awarded.

Education Secretary Gavin Williamson has congratulated “hard-working” students ahead of a nerve-racking morning for the nation’s 16-year-olds.

He said pupils “should feel proud of their achievements” and noted there have “never been so many options available” for those leaving secondary school.

Data surrounding the proportion of top GCSE grades will emerge later this morning – and it comes two days after college and sixth-form students received their A-level results.

More than 190,000 18-year-olds in England were able to take up their first-choice university place as A-level students received more A and A* grades this year than ever before.

A-level, AS-level and GCSE exams were cancelled in January due to the ongoing disruption caused by COVID-19.

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Instead, teachers have used mock results, coursework and in-class assessments to determine students’ grades this summer.

Overall, 44.8% of students were awarded A or A* grades this year, compared with 38.5% in 2020.

Experts have warned that the new teacher assessments are causing grade inflation and “lower standards to become the norm”.

The number of students with A* grades has also risen dramatically – by 19.1% – which is the highest figure since they were introduced in 2010.

Professor Alan Smithers, director of the Centre for Education and Employment Research at the University of Buckingham, said: “Plentiful top grades make pupils and parents happy, but they are less helpful for those using the grades for admission to the next stage of education or recruitment to employment.

“With another bumper crop of top GCSE grades, the future of exams at age 16 is likely to come under threat.

“There is already a pressure group to ditch them and if parents get a liking for plentiful top grades they may become involved.”

Acknowledging that students and teachers alike have faced “unprecedented disruption”, Mr Williamson added: “There have never been so many great options available for young people, whether that’s going on to study A-levels, our pioneering T Levels, starting an apprenticeship or a traineeship. Whatever option young people choose, they can do so with the confidence it will give them the skills and knowledge to get on in life.”

Minister for apprenticeships and skills Gillian Keegan added that there are “seven new pioneering T Level qualifications” being launched from September, including healthcare, science and on-site construction.

Labour are calling on the government to deliver a £15bn package of support to schools to give them the resources they need to deliver new activities including sports, drama, music, book clubs and targeted academic catch-up and small group tutoring “for all who need it”.

Analysis carried out by the party suggests an estimated 346 million days of face-to-face school time have been lost this year.

Labour leader Sir Keir Starmer will visit a school in Swindon today to meet students receiving their GCSE results and urge the government to adopt Labour’s Children’s Recovery Plan.

The Opposition is warning that an estimated 560,000 Year 11 students are leaving school this summer without any catch-up support due to a “lack of ambition” from the government.

Shadow education secretary Kate Green claimed that the government has treated children “as an afterthought”.

She said: “Ministers have now compounded this failure with an utterly inadequate recovery plan which will leave millions of children without any additional support, showing a shocking lack of ambition their future ambitions and life chances.”

The comments come as The Guardian newspaper reported Sir Keir has called on Prime Minister Boris Johnson to sack Mr Williamson for failing children during the pandemic and presiding over a “yawning gap” in attainment between private and state school pupils.

It is rumoured that the education secretary could be replaced at the next reshuffle.

A government spokesperson said: “We have committed to an ambitious and long-term education recovery plan, including an investment to date of over £3bn and a significant expansion of our tutoring programme, to support children and young people to make up for learning lost during the pandemic.”