Pupils will face fewer exams under a review of Conservative education policy being drawn up in response to concern about overtesting in schools.

The new policy document, being drafted by a Tory policy review group, is expected to recommend the downgrading of national curriculum exams at age 14 and more assessment by classroom teachers.

The move is likely to open up a new front in the battle between David Cameron and traditionalists in his party. Last night the Conservative leader faced his fiercest criticism yet over his education policy, as the party grandee Norman Tebbit accused him of “rebranding [the party] to implement new Labour policy”. Mr Cameron defended his decision not to create any more grammar schools as a “key test” of whether the Tories are fit to govern. He caricatured his critics as a “right-wing debating society muttering about what might have been”. But he later suffered his first defection over the issue.

David Pickles, a councillor who sits on Sutton council, in southwest London, switched to UKIP saying that Mr Cameron’s claim that the 11-plus holds back poorer children was astonishing. “What right do a group of former public school boys have to halt social mobility in this way, and instead support the city academies which are nothing more than a vanity toy for rich men?”

Lord Tebbit, former Tory party chairman, said: “My own party has now rebranded itself as the party to implement new Labour policies more effectively. God knows there is need of a party to do that, but I thought it was the Labour Party.”

Mr Cameron has sought to reassure traditionalists, saying that he is determined to improve discipline and scrap “faddish” teaching methods.

But The Times has learnt that he may face a new battle with the right of his party as his policy review group prepares to recommend a reduction in testing. A senior member of the policy review group told The Times: “We want fewer, but tougher exams. We are overexamined and overtested as a nation, but the confidence of the public, universities and employers in standards has been eroded so we need a tougher system.

“Testing at age 7 and 11 is important, but a lot of people are questioning whether key stage tests at age 14 are fit for purpose? Teacher assessment might be one alternative.”

Mary James, deputy director of the Teaching and Learning Research Project at the Institute of Education at the University of London, who has submitted a report to the party’s policy review group on education, is also a strong opponent of the existing system.

“The current testing system carries too much weight because it is being used for too many purposes – to evaluate pupils, teachers and schools. We need different assessment systems for different purposes,” she said, speaking in a personal capacity.

Schoolchildren in England are the most tested in the world. They sit national curriculum tests at key stages 1 (age 7), 2 (age 11) and 3 (14), which form the basis of school league tables. But critics say that these encourage schools to drill children to pass tests, resulting in a narrow curriculum and undue pressure on pupils and teachers.

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