The single biggest threat to free speech on university campuses is the Government's counter-terrorism Prevent programme, according to a report.

The paper written published by the Higher Education Policy Institute (HEPI) claims despite "strong rhetoric supporting free speech in universities", the "current single biggest threat to free speech on UK campuses currently comes from the Government's own Prevent programme".

Author of the report Corey Stoughton, an advocacy director at human rights group Liberty, said Prevent had a "demonstrable chilling effect on free speech in universities".

She added: "Recognising that not everyone has equal access to speech, and that some people are disproportionately harmed by speech, doesn't justify giving powerful institutions more power to censor speech."

The report said: "Through the so-called Prevent strategy, the Government imposes obligations on universities and members of university communities that either directly interfere with speech or have the foreseeable and actual effect of chilling the exercise of free expression.

"Section 26(1) of the Counter-Terrorism and Security Act 2015 imposes on universities a duty to 'have due regard to the need to prevent people from being drawn into terrorism.'

"Statutory guidance on this duty requires universities to check that speakers are not likely to express 'extremist' views and, if they may express such views, to either take steps to limit the speech or, if they cannot limit the speech to manage the risk, force the cancellation of the event."

The Home Office's definition of extremism was not "coherent or workable", the report said, adding: "The desire to interrupt the process of radicalisation is a laudable one, but we cannot let that desire override the very liberties and values that many of today's terrorists seek to threaten."

HEPI director Nick Hillman said the report would challenge ministers to "be more careful when they are tempted to impose new restrictions on free expression."

He added: "There are few justifications for limiting free speech beyond current laws.

"That is true whether it is students wanting to block provocateurs from speaking or Government ministers mixing up the prevention of terrorism with blocking legitimate free expression."

The Home Office has been contacted for comment.

By Flora Thompson