A headteacher accused by Gary Lineker of treating sixth formers as “guinea pigs” after switching from A-Levels to the Cambridge Pre-U has hit out against criticism of the new qualification.

Reverend John Witheridge, head of the prestigious Charterhouse School, Surrey, came under fire from the former England football captain after his son, a pupil at the school, failed to get the grades demanded for his university offer.

Reverend Witheridge said the Pre-U, taken by pupils at 59 schools for the first time this year, had got students “intellectually excited” again after they had become bored with A-level.

He said the exam, whose grading system allows pupils to demonstrate their ability above and beyond an A-level A* grade, may even have contributed to an increase in the number of pupils at the school going to Oxbridge.

Parents, he said, had given a “very favourable” reaction to the swap to Pre-U, and the vast majority of pupils had met their university offers.

“Both pupils and teachers have enjoyed the work, they have certainly worked hard,” he said. “It’s such an exciting age, once you’re studying subjects you have chosen. It would be a scandal to bore students.”

He denied the Pre-U was elitist, despite 59 per cent of candidates this year attending private schools.

“I would be embarrassed to be taking it if it was an exclusive posh qualification,” he said.

He said that Michael Gove’s expressed plan to remodel A-Levels based on the Pre-U could take several years, but there was nothing stopping schools from following the syllabuses now. Forty-five state schools and 56 independent schools are entering pupils for the Pre-U in 2011 or 2012.