Concerns about cheating and over-generous teacher marking mean that pupils’ practical science work will no long count towards overall A level grades, under plans from the exams regulator announced today.

Ofqual’s proposals for reformed A levels - to be introduced from 2015 - will also mean a reduction in coursework in English, history and computing; but less emphasis on exams in geography.

At the moment between 20-30 per cent of A levels in biology, chemistry and physics are made up of practical coursework.

But in a consultation launched today Ofqual says they should become 100 per cent exam assessed. A requirement for practical skills would remain, but the assessment of them would be reported separately from the main A level grades.

Justifying the change, the regulator notes that current arrangements for A level science practical work leave open “the possibility of malpractice”.

It is impossible in some schools for all assessments to take place simultaneously, forcing exam boards to allow them to take place over a period of time “during which it is almost impossible to keep the nature of the task confidential”, Ofqual says.

“We are concerned about the increasing number of allegations of malpractice in the conduct of these assessments,” the consultation document adds.

“For example, this year we were alerted to 53 investigations into alleged teacher or student malpractice in respect of one exam board’s A level practical science assessments.

“We believe the actual number of incidents is likely to be higher, as not all will come to light.”

The regulator also raises serious concerns about teachers’ marking of these assessments, noting that students’ do much better in them than in their exams, “particularly in chemistry”.

“The range of marks allocated to students by teachers marking the practical assessments is at the top end - and in the worst cases the most frequently occurring mark is 40 out of 40,” Ofqual says.

Other reasons it gives for taking practical work out of the science A levels include a failure to “discriminate well between students” and because the teaching of wider practical skills can be constrained by a focus on those likely to be tested.

Lastly it says exam boards have had no “verifiable evidence” of students’ practical skills, limiting their ability to moderate teachers’ marking.

From 2017, when the first new A level results are due, Ofqual proposes that outcomes of practical assessment should appear on pupils’ certificates but not contribute to the overall grade.

The proposal echoes the new arrangements for GCSE English where speaking and listening is still assessed but will no longer count towards the main grade.

In A level geography all fieldwork skills and understanding are assessed in the conventional exams that make up 100 per cent of the current qualification.

But after consulting geography teachers and academics Ofqual says this should change, with a fifth of the new A level made up from non exam assessment of fieldwork.

Ofqual recommends that English literature and language, and computing should all see the proportion of coursework contributing to overall A levels shift from the current 15-40 per cent to 20 per cent. In history it will also go to 20 per cent, from 15-20 per cent.

Psychology, business, economics and sociology will all remained completely exam assessed. Art and design will remain all coursework.

The main change in the A level reforms, begun by education secretary, Michael Gove, will be the shift from the existing AS/A2 modular system to linear A levels with stand alone AS levels.

That reform has been opposed by both Oxford and Cambridge universities. They were two of the elite higher education institutions that Mr Gove originally said he wanted to take ownership of the new A levels - an offer that was effectively rejected.

The education secretary has also been forced to delay the reforms by a year. But independent school heads warn that they are still “high risk” and could lead to invalid grades.

Today Ofqual noted that: “Despite the changes we are proposing A levels and AS qualifications [that] will remain substantially the same qualifications as at present.”

The regulator’s consultation runs until January 17. The Department for Education has begun a separate consultation on content for the new qualifications.