Some of Britain's most high-profile public intellectuals have formed a coalition to defend universities against the erosion of academic freedom and the marketisation of higher education.

Lord Bragg, Alan Bennett, Sir David Attenborough and Richard Dawkins are among 65 writers, broadcasters and thinkers who have jointly founded the Council for the Defence of British Universities (CDBU), to be launched next week.

The group's manifesto, also backed by former poet laureate Sir Andrew Motion, Booker prize-winner Dame AS Byatt, playwright Michael Frayn and astronomer royal Lord Rees, claims the basis of a degree is under threat.

Writing in the Times Higher Education supplement, historian and former British Academy president Sir Keith Thomas said "the very purpose of the university" was being "grossly distorted by the attempt to create a market in higher education".

Students, he wrote were "regarded as 'consumers' and encouraged to invest in the degree course they think most likely to enhance their earning prospects".

Academics, he added, were now viewed as "producers, whose research is expected to focus on topics of commercial value and whose output is measured against a single scale and graded like sacks of wheat".

The organisation is expected to campaign for the abolition of government funding bodies and propose a move to fully independent grant councils free from political interference.