Postgraduate students are going to be used on a larger scale this year to mark exam scripts.
Marking is traditionally piece work for teachers
The move comes amid concerns about a shortage of markers in some subjects.
A pilot scheme last year was judged to be a success and the wider use of postgraduates has been approved by the Education Secretary, Charles Clarke.
Exam boards are assuring students they will have enough markers to handle all the exams.
Marking is a "cottage industry", to quote the head of the exams regulator, Ken Boston of the Qualifications and Curriculum Authority (QCA).
Millions of scripts are posted around the country to markers who are often teachers working in their spare time on a piece rate.
The task has grown considerably in recent years, in particular with the introduction of the new AS-levels exams in 2001. Some 24 million GCSE and A-level scripts will need to be checked this year.
Last year one of the big boards, Edexcel, ran a pilot scheme using student history teachers to mark GCSE history papers.
Edexcel said it had used 16 postgrads last year in the trial and would be employing about 110 this year.
A spokesman said: "We will use experienced examiners in preference first."
Another part of its effort to cope is asking experienced examiners to take on "a few more" than the minimum allocation of 250 scripts in the shortage subjects - notably English, history and IT.
But one who will not be available - having just resigned from the job - is Adam Oliver, who teaches A-level English at a school in Oxfordshire.
He marked 260 English essays for Edexcel last year, his third year as a teacher and the first time he had done any marking.
This year he says he was asked by Edexcel, "as an experienced marker", to take on 400 scripts.
He says this would have meant checking a 1,000-word essay every six minutes, whereas it takes him 12 to 15 minutes to do the job properly.
So he has resigned as an examiner.
He would have been part of the scheme under which the Department for Education has made available £6m to compensate head teachers for finding temporary staff while their teachers mark scripts full-time in a secure room.
Mr Oliver said he was disappointed because this so-called centre-based marking had been a chance to "re-professionalise" the system and restore confidence in A-levels.
Instead, "teachers will have to work really quickly and mistakes will be made".
A spokesman for Edexcel said any of its examiners could turn down the extra workload.
The root of all the problems is the sheer volume of exams.
Mr Oliver said: "My general feeling is that the system was, several years ago, quite a good one - but has been overloaded."
The Joint Council for General Qualifications - representing all the exam boards in England, Wales and Northern Ireland - is happy with the use of postgraduate markers.
It says their performance in last year's trial was "above average".
Spokesman George Turnbull said they had been given training for the role and had been closely supervised.
"It was a successful experiment and it's being extended where it can be."
He said the fact that they were not qualified teachers was irrelevant - teachers did not necessarily make good markers, and good markers were not necessarily teachers.
"The important thing is that people are appropriately qualified and able to keep to a mark scheme and mark on time to an appropriate standard."
Of the shortage of markers, Mr Turnbull said: "Things are fairly similar to other years in many ways - in some subjects there's a glut, in other subjects perhaps some more would be helpful.
"One of the things we do guarantee is that the examinations will be marked on time and to standard. Arrangements are in hand and we are all confident."
A spokesperson for the Department for Education said it was up to awarding bodies to decide how best to allocate scripts to examiners.
"We look to the QCA to meticulously monitor and regulate standards and the examining bodies themselves have rigorous systems in place to ensure high standards and efficiency."