The outcome of the appeals process has been very disappointing and there are many youngsters who have not received the grades they should have

Gordon Mackenzie, headteachers' association

Gordon Mackenzie, the association's president, said: "Our members are very very concerned that so few appeals were granted.

"When we submit appeals we do so on the basis of estimated results from teachers which are based on evidence gathered throughout the year.

"The outcome of the appeals process has been very disappointing and there are many youngsters who have not received the grades they should have."

A poll of headteachers revealed more than 100 "serious concerns".

Failures admitted

Mr Mackenzie said schools' estimates were generally accurate and several universities had used them this summer as a basis for accepting pupils.

The association's comments came on Thursday, the day before the Scottish Parliament's Education Committee was due to publish its report into the exams fiasco.

Speculation was rife that former education minister Sam Galbraith would come under fire in that report.

Sam Galbraith: Could be criticised by the education committee

The SQA admitted to a number of failures when thousands of pupils had received late, incomplete or inaccurate exam certificates.

The headteachers' association said parents had expressed concerns that students who had sailed through their prelims were awarded below-par grades.

Mr Mackenzie said: "It's about fairness and once we have the analysis we will speak to the SQA and we want them to take it forward, to look at our analysis and work out a structure which will result in fairness."

A spokesman for the SQA said headteachers had not yet discussed in detail their concerns.

He added: "We are more than happy and indeed view it as healthy to sit down and listen to those concerns and work through them in order that they can be addressed."

The SQA dealt with 40,800 Higher and Sixth Year Studies appeals this year which was double the usual number.