The government’s already ambitious exam reform programme is gathering pace and being extended to more subjects including the arts, technology and PE, it will be announced today.

Education secretary Michael Gove will unveil plans for nine new GCSEs and six new A-levels, all with “more demanding content” and all to be introduced in 2016, alongside previously announced changes in several other subjects.

School leaders are warning that the packed timetable for change will put “enormous pressure” on heads and teachers who are also introducing a new national curriculum this year.

New tougher GCSEs, with grades set at 9-1 instead of A*-G, will be introduced in art and design, music, drama, dance, citizenship, computer science, design and technology, PE and religious studies.

The Department for Education (DfE) has already said that reformed GCSEs in languages, history, sciences and geography will come in from 2016 and their finalised content will be announced later today.

Content for overhauled English literature and English language and maths qualifications that will reach schools a year earlier from 2015 was published in November.

Heads leaders are happy that the big-bang approach to reform will limit the problems that could come through using old and new GCSEs simultaneously.

Brian Lightman, Association of School and College Leaders general secretary, said: “Running two systems in tandem is problematic and potentially confusing for parents, schools, employers, FE and HE, so to move to one system would be preferable.”

But he fears that the pace and volume of change that schools now face is “immensely ambitious”.

Reformed A-levels in music, drama, dance, design and technology, PE, and religious studies will be introduced in 2016, it will also be announced today. They will come in alongside reformed A-levels in maths, further maths, languages and geography.

Mr Gove said the changes were “fantastic news for cultural education in England’s schools”.

“I am passionate about great art, drama, dance, music and design, and I am determined to ensure that every child enjoys access to the best in our culture,” he said. “I also want all schools to be able to nurture creative talent in every child.”

The DfE said that content for GCSEs and A-levels announced today would be developed by exam boards, advised by “subject experts” such as Dyson, the Arts Council England, the Design and Technology Association, the Incorporated Society of Musicians, the British Computer Society and the Religious Education Council.

A-level content will also be based on the advice of university academics.

Mr Lightman said: “They are very ambitious changes and their success will be dependent on effective implementation and high quality communication and preparation for schools from the awarding bodies.

“We have said all along that we are worried about the amount of simultaneous change which is putting enormous pressure, not only on schools, but on the awarding bodies and on Ofqual.”

An earlier raft of reformed A-levels in art and design, business, computer science, economics, English literature, English language, English language and literature, history, biology, chemistry, physics, psychology and sociology will be taught from September 2015. Content for these subjects will be announced later today.