Just two pupils in England could end up achieving top grades in all their GCSEs under the new grading system, the Department for Education's chief analyst has predicted.
The government is gradually replacing the current A* to G grades with numerical grades, from 1 to 9 – with 9 being the highest.
Just 20 per cent of those who would have achieved A or A* under the existing system will be awarded a grade 9.
Responding to a tweet about the number of pupils who would get straight 9s, Tim Leunig, the DfE's chief analyst and chief scientific adviser, wrote: “2 is my guess – not a formal DfE prediction. With a big enough sample, I think someone will get lucky...”
The suggestion that so few pupils will get top grades across the board has exacerbated concerns that the new system could increase the pressure on top-performing pupils.
Last year, Caroline Jordan, then president of the Girls' Schools' Association, said independent schools were downplaying the importance of the new grade 9 to parents and pupils to preserve students' mental health, and warned that the “days of all bright pupils getting 10 A*s are over”.
Setting the grade 'far too high'
When told about Dr Leunig’s tweet, her successor Charlotte Avery, who is also headmistress of St Mary’s School, Cambridge, said schools had not known grade 9 would be this difficult.
She told Tes: “If the top grade is so unachievable, I think this is setting the grade far too high.
“We are almost setting up many of them to feel that they are failing, if that is the level of difficulty.
“It demoralises the school and the child and the parents, who are all working so hard to make education so enjoyable and successful.”
The new grading system is being phased in over three years.
It will be used for English and maths exams taken this summer, with 20 more subjects following next year, and most others in 2019.
Last week, Sally Collier, the new chief executive of the exams regulator Ofqual, told Tes that some parents and employers would be confused by the new grading system, and Ofqual had a big job communicating the changes.