Exam boards issued 2,715 penalties to students for malpractice in 2017 against 2,180 in 2016, Ofqual said.

Most were penalised for taking mobile phones into the exam, while just under a fifth were pulled up for plagiarism.

The rise in cheating came as new tougher GCSEs in English and maths were introduced for the first time.

Exams regulator Ofqual, which published the figures, describes malpractice as any breach of the rules which might undermine the integrity of an exam.

Staff penalised

It also covers any attempt by students to communicate with each other during exams, as well as the failure of a school or college to follow exam board instructions.

The failure by staff to follow rules around controlled assessments and coursework, is covered, as well as the conduct of examinations.

There was also an increase in the number of school and college staff penalised for malpractice.

'High stakes'

Ofqual issued 890 penalties to staff in 2017 compared with 360 the previous year.

Four in 10 student penalties were for taking unauthorised items, mainly mobile phones, into the exam room.

Plagiarism was the second most common form of malpractice, with 86% of this occurring in maths and computing exams.

Most students, 1,235, were penalised with the loss of marks.

Some 635 students were given a warning and 490 had their papers scrapped.

Liberal Democrat education spokesperson Layla Moran said: "This is an extremely worrying trend in our exam halls and throws into question whether the current assessment process is even fit for purpose."

She said it was the impact of a system which puts enormous pressure on teachers and students, "making them feel like they will succeed or fail based on only a few hours of narrowly focused, high stakes exams".