THOUSANDS of students across the country face having another two-week wait as their exam grades are reviewed after the education system was thrown into fresh chaos yesterday.

Former chief schools inspector Mike Tomlinson announced that the grade boundaries for many AS and A-level subjects would be re-examined and students' results changed accordingly.

Downing Street refused to comment, but Tony Blair's eldest son, Euan, may be among those caught up in the re-grade process.

It is believed he took A-level French - a problem subject for all the boards - and his London school said last month that it had queried grades in exams set by Oxford and Cambridge and RSA (OCR).

Euan had a conditional offer from Oxford but is off to Bristol instead, where he is reading ancient history.

Mr Tomlinson, who led the inquiry into the A and AS level fiasco, said he hoped students would get their new grades by October 15, ending weeks of uncertainty.

Schools and universities in the North-East and North Yorkshire are bracing themselves for a rush of students desperate to use their corrected grades to claim their rightful places on degree courses.

But Malcolm Wilson, director of studies at Yarm School, Teesside, warned: "Students are already at university and may not be able to change courses until next year.

"This will mean a lot of upheaval as students are forced to take a gap year they had not planned for.

"Then what happens next year? If more students are given deferred places, there will be less places for next year's students to take up. This is just the first step on the road to sorting this out."

Education Secretary Estelle Morris has promised to give universities the necessary funds to accommodate students' wishes.

But those across the North-East said it is too soon to say what the effect would be on students who had been refused places or wanted to change courses.

The re-grading will cover 104 units in subjects at AS and A-level units and could mean more than 304,000 grades are reviewed.

At Ampleforth College, near York, it is thought more than 100 young people could be affected by the regrading.

Announcing the regrading, Mr Tomlinson stressed no individual was to blame for the fiasco, which was caused when examiners tried to realign the new exams with the old A-level system.

His second report in November will make recommendations to try to avoid the same chaos next year, but this is little comfort to those waiting for new grades.

Eighteen-year-old Raman Sinha, from Eaglescliffe, near Stockton, believes his generation have been used as guinea pigs to test the new exam system.

"This might mean these problems never happen again but what good is that to us?" he asked. "Some of my friends have missed out on both their first and second choices and have gone through clearing.

"Now they have decide whether to stick with what they have or go through all this again."