A union boss and former Suffolk headteacher has struck out at the government over their decision to allow students to use mock exam grades in place of predicted A-level results.

Geoff Barton, General Secretary of the Association of School and College Leaders has lamented the decision which he says undermines teachers and leaves parents, students and school with little guidance.

The former headteacher at King Edward VI School, Bury St Edmunds released a statement today after the changes were revealed on Tuesday, less than 48 hours before students are due to pick up their results.

The changes will allow students unhappy with their results, which have been predicted by teachers before then being moderated, to appeal.

This would see them to use grades achieved in mock exams while applying to universities.

Mr Barton said: “The sudden announcement that mock results could be used by students if they are higher than calculated grades is bewildering.

“Mock exams are taken at different times, involve different papers, and some students won’t even have sat them.

“Teachers will have felt undermined by this decision given that they have spent the last few months painstakingly assessing their students and providing centre-assessed grades to the exam boards.

“Obviously the concern is what happens when these centre-assessed grades are standardised by the exam boards, and it seems as though the eleventh hour idea of falling back on mock exam results is an attempt to head this off at the pass even though it doesn’t make any sense.

“There is no guidance over how this will actually work, so our members are now left in a position where they will have to field questions from parents and students without any information. It is chaos.”

Thousands of pupils are expected to see their results downgraded by moderators when they are released tomorrow.

Many have expressed their concerns over the moderation of results which is said to reflect the reputation of schools.

It is said to disadvantaged highly achieving pupils who attend school which historically have not performed well.

Schools minister Nick Gibb insisted the Government had nothing to apologise for by acting so late in the day in England, adding it would only affect a small number of students.

He said: “There is no confusion. We have been very clear from the very beginning. We had to have a system in place to award qualifications to young people given that we had cancelled the exams.

“We apologise to nobody for finding solutions, even at the 11th hour, to stop any student being disadvantaged by this system.”