Maths A-level is expected to have the lowest pass mark in history, as experts predict that a financial incentive for schools may have led to a weaker cohort.

This summer was the first year that pupils of all abilities took the new, reformed Maths qualification which was designed to be more challenging and better prepare sixth form students for university.

But students complained that they found the Edexcel exam exceptionally difficult, with thousands signing a petition to demand “some form of compensation” or “special consideration” since questions were “unlike any specimen, past or textbook questions”.

A separate petition claimed that students’ hopes of attending university have been “shattered” thanks to the Maths exams.

Experts have said that a new Government policy, where schools are offered a cash incentive of up to £2,400 for every extra student that takes Maths in the sixth form, may have played a role.

Barnaby Lenon, chair of the Independent Schools Council, said: "This is the first cohort taking Maths A-level encouraged to do so by the extra money that schools get.

"What that means is, you may have a group of weaker students taking Maths A-level than there were in the past. It may be that you only need low marks to get reasonably high grades due to the combination of students and hard exams."

Research by the exams watchdog last year found that up to 40% of GCSE and A-level exams may be awarded incorrect grades due to inconsistent marking.