The exams regulator has dealt a major blow to the Government’s flagship Diploma qualification, revealing that one of its key elements may be dropped.

Kathleen Tattersall, head of Ofqual, said the radical surgery was being considered as schools, colleges and exam boards prepared for the controversial Diplomas to be offered to more pupils.

The chief regulator says in her second annual report, published yesterday: “It is becoming clear that in the longer term there may need to be some simplification of the (Diploma’s) structure if it is going to be taken by large numbers of students.”

She told The TES there was a need to review “whether you have made the right call in terms of the nature of, and the range of, components that you are expecting students to perform in”.

“What we as Ofqual will be doing, and certainly others with an interest in the Diploma will be doing, is asking the question of whether we really do have the balance right between principle learning, functional skills or indeed the extended project,” she said.

Asked whether that could mean taking one of the elements out altogether, Ms Tattersall, said: “That is always a possibility.” But she refused to say which elements were at risk.

Her comments are the latest blow to the troubled Diploma. This month it emerged that a Conservative government would free schools from the responsibility to make all 17 Diplomas available to all pupils at all levels.

The Tories have already said they would scrap the academic Diplomas in science, languages and the humanities, due to begin in 2011, and research has shown that top universities have concerns about the “likely academic rigour” of Diploma content.

Exam boards have warned that the hugely complex qualifications are being rushed in and described the Government’s aim of them becoming the “qualification of choice” by 2013 as “fantasy”.

Diplomas comprise a principal learning unit, functional skills tests, additional and specialist learning modules, work experience and an extended project. They will often require the involvement of several different exam boards before a pupil can be awarded a final grade.

Ms Tattersall said the demand for functional skills should remain part of the Diplomas. But her report says the functional skills tests have “some way to go before they can be regarded as fully satisfactory”.