Thousands of students are to have their grades reviewed, the head of the inquiry into this summer's A-Level exams fiasco said today.

A total of 31 subjects are affected - all but seven of them involving exams set by the Oxford and Cambridge and RSA (OCR) exam board.

They include English Literature and English Language A set by the Assessment and Qualifications Authority and OCR, and French set by all three exam boards, including Edexcel.

The re-grading will cover 104 individual AS and A2 units out of a total of 1,438, for which the total number of entries was 304,205.

Former chief schools inspector, Mike Tomlinson, who led the inquiry, hopes the process can be completed by October 11, ending weeks of uncertainty for thousands of students.

The fact that their entries were wrongly graded by examiners, who were attempting to ensure parity of standards between the old and new versions of the A-Level, has forced the Government to postpone the publication of secondary school league tables.

The tables were due out in November but the Department for Education and Skills said they would not be published until ministers were certain they were based on ''reliable'' figures.

The announcement of which subjects have to be re-graded was expected on Tuesday but Mr Tomlinson gave the exam boards, Oxford and Cambridge and RSA (OCR), the Assessment and Qualifications Alliance (AQA) and Edexcel more time to ''double check'' their work.

OCR faced the most complaints about ''bizarre'' grades and was likely to have most of the re-grading work to do, while the other boards have insisted few, if any, of their exams were affected.

Mr Tomlinson said he expected the total number of affected subjects to be ''around 12'' when he unveiled his first report on what happened to A-Levels in summer 2002 last Friday.

He found no evidence of political interference by ministers to make A-Levels appear tougher, but ruled that a lack of understanding about standards of the new version introduced in 2000 ran right through the system.

The confusion caused examiners, obliged to maintain standards in line with previous years, to adjust grade boundaries in such a way as to penalise some students and Mr Tomlinson said a re-grade was necessary to sort out the mess. Students who have started degree courses and whose grades end up being changed will have to decide whether to stay at their university even if it was not their first choice, try to change mid-year, or take up their first preference place next year.

Universities have said they will do their best to accommodate everyone's wishes, and Education Secretary Estelle Morris has promised to give them the necessary cash to do so.

In his report last week Mr Tomlinson called the problems ''an accident that was waiting to happen''.

The second report of his inquiry, due in November, will focus on what needs to be done to prevent the drama of the last few weeks from happening again.

He is also investigating the validity of AS-Level grades, as the confusion about standards which hit A2s, as the second half of the new A-Levels are known, was common to the exams taken by lower sixth formers this summer, he said.