More than 200,000 sixth-formers who will get their A-level grades this week have been the guinea pigs for the new grading regime

The marks required to secure top grades in the first tougher new GCSE and A-level examinations have been lowered to avert a drama­tic fall in results this summer, The Sunday Times can reveal.

The biggest exam shake-up in a generation — the brainchild of Michael Gove, the former education secretary — had been designed to drive up standards, bring England into line with top-performing ­systems in the Far East and identify academic high-flyers for the best universities.

Critics said the exam regulator’s decision to lower the mark ­thresholds needed for good grades made the reforms pointless, especially if it becomes routine.

Sally Collier, chief regulator of Ofqual, said: “I want the message to be that students have done fantas­tically well. All our kids are brilliant.