Image caption Mr Gove has said there is an urgent need to revamp exams

Much of the government's plans to revamp England's exams system are being delayed by a year because of concerns by the exams watchdog, Ofqual.

Education Secretary Michael Gove wanted new O-level-style GCSE exams and tougher A-levels introduced in 2015.

But Ofqual said it could not be confident "high-quality GCSEs" or new A-levels in maths and modern languages would be ready so soon.

Mr Gove accepted the exam boards needed more time to get it right.

The education secretary has been clear he is in a hurry to change the exams system, describing the current GCSEs as "not fit for purpose".

But teaching unions, head teachers, examiners and elite private school leaders have expressed concerns about the pace of change to the system.

We have to balance the urgency of fixing exams against the dangers of repeating past mistakes. Mr Gove's spokesman

The regulator, Ofqual, warned soon after the shake-up was first announced that it would intervene if it thought the programme of reform was moving too fast.

In a letter to Mr Gove, just published on the Ofqual website, chief regulator Glenys Stacey wrote: "It is clear that the amount of work needed on GCSEs, including the development of strengthened regulatory arrangements, means we cannot be confident that new, high-quality GCSEs in all subjects could be ready in good time for first teaching from 2015."

The exams regulator says it will focus on the new GCSEs in English literature, language and maths - the subjects with which there are the "biggest concerns" - and hopes to have these ready for first teaching in September 2015.

But the new GCSEs in science, history and geography will be delayed until 2016.

Ms Stacey added a review looking at the planned new A-levels had found "fundamental" work was needed on maths and further maths.

More time would also be needed for new A-levels in modern languages, she said.

'Urgency'

Mr Gove wrote back, saying he had agreed the reformed GCSEs should be "re-phased".

In the letter, dated 6 September, he says: "We must replace the modular GCSE treadmill with exams that encourage the skills universities and employers want, such as essay writing and mathematical problem-solving.

"That is why I wanted new GCSEs in core academic subjects to be in place for teaching from 2015.

"However, I accept that much more rigorous regulatory demands should be put in place and that Ofqual needs more time to develop them."

A spokesman for Mr Gove said: "Existing GCSEs encourage a 'memorise and regurgitate' approach to education.

"We urgently need to replace them with tests that encourage higher level skills such as essay writing, mathematical modelling, and problem-solving.

"Ofqual thinks that the necessary changes are so big that they and the exam boards need more time to make sure they get things right.

"We have to balance the urgency of fixing exams against the dangers of repeating past mistakes.

"Focusing on English and maths first makes sense.

"Many people have opposed reforming exams and criticise us for moving quickly - but if schools and exams don't change quickly, even more children will be failed."

Christine Blower, head of the NUT, said: "It was always a ridiculous idea of Michael Gove's that such massive changes to the examination system could be carried out so quickly.

"This delay will now enable the content and structure to be considered in greater detail."

She added: "It is useful for Ofqual to prioritise English and maths specifications as the first syllabuses to go into schools and colleges, but all the new qualifications should be trialled and evaluated before being introduced."

Russell Hobby, general secretary of heads' union, NAHT, said: "If the government is struggling to design the new exams in the timescales envisaged how much harder will it be for schools to develop programmes, write materials and train staff at the same pace? More haste less speed."