The onus placed on universities by the government’s new counter-extremism strategy will lead to inoffensive and bland campus debates without preventing any student radicalisation, according to the former business secretary Vince Cable.

The former Liberal Democrat MP instead says that banning extremist speakers from universities may in fact exacerbate the problem by driving underground hitherto non-violent extremists.

In a speech to the Institute of Advanced Legal Studies on Tuesday, the former coalition cabinet minister will say that the new obligation on universities to balance free speech with counter-extremism is highly problematic.

“Instead of intellectual challenge there will be a bland exchange of views which are inoffensive and politically correct,” says Cable, according to an advance copy of his speech provided to the Guardian.

“This will not stop terrorism or terrorist recruitment, and may make the problem worse by driving underground those who are regarded as extreme but are currently non-violent.

“It seems highly likely that university authorities in particular will be risk averse and will seek to avoid the danger of legal action from the authorities in respect of extremist speakers.”

Cable is the latest senior public figure to criticise the government’s new counter-extremist strategy as counterproductive.

Several police chiefs and David Anderson QC, the independent reviewer of terrorism laws, have already voiced concern that David Cameron’s counter-extremism bill, which will ban non-violent extremists, risks provoking a backlash in Britain’s Muslim communities and playing into the hands of terrorist recruiters.

Last week, Sir Peter Fahy, chief constable of Greater Manchester police, told the Guardian that the government’s latest plans could be counterproductive, coming at a time when Muslims in the UK feel increasingly alienated.

Fahy, who speaks for the police on the government’s Prevent strategy, said: “There is a concern that efforts to control extremist narratives will limit free speech and backfire if we don’t get the balance right. The efforts to control extremism and limit protest by those caught by too wide a definition may undermine the very rights and British values you seek to protect.”

Theresa May, the home secretary, has unveiled a string of anti-extremist measures, including a major drive against “entryist” infiltration of the public sector, charities and businesses by Islamist and other extremists as a key part of the government’s counter-extremist strategy. May also proposed banning orders on non-violent alleged extremists, threats to close mosques, and bars on alleged extremists working with children and vulnerable people.

Cable – who lost his Twickenham seat in this year’s general election – questions, however, whether extremist views such as the rejection of the democratic system and core human rights for women are in any way predictors or precursors of terrorism.

He will say: “A key target is Salafism, which is a particularly austere form of Islam with doctrine that fits comfortably within the definition of extremism because of an uncompromising approach to other faiths. However, leading UK Salafists have strongly opposed terrorism and, indeed offered to help the authorities in countering the attraction of terrorism amongst young people.”

Cable reminds his audience that Gordon Brown, the former prime minister, made himself look foolish with attempts to define “British values”.

What is dangerous, though, says Cable is “when these very subjective judgments are used as the basis for legal sanctions and for suggesting that there is a link to terrorism. A good test of whether legislation is necessary is the demonstration of evidence. There is little credible evidence to suggest an inevitable causal link between holding ‘extreme’ views and terrorism”.

The hunt for extremists in universities and across the public sector follows the Trojan horse affair in Birmingham schools. The Home Office defines entryism as extremist individuals, groups and organisations consciously seeking to gain positions of influence to better enable them to promote their extremist agenda.

The strategy says: “The review will clearly set out the risk posed and advise on measures to guard against entryism, for example by improving governance, inspection and whistleblowing mechanisms. It will also engage charities and businesses to help them identify and tackle entryist behaviour.”

Cable says legal provisions of the 2014 Counter-terrorism Act already extends Prevent duties to the public sector including schools, nurseries and the NHS.

He said: “The idea that nurseries should be sniffing out subversive toddlers for the caliphate belongs to Monty Python rather than the real world, but the combination of existing powers with those envisaged in the new counter-extremism legislation is anything but funny.”