The government’s counter-terrorism programme has been too focused on rightwing extremism and should now crack down on Islamist extremism, according to leaked draft extracts from a landmark review of the Prevent strategy.

In one particularly provocative recommendation, seen by the Guardian, the review claims there has been a “double standard” approach to tackling different forms of extremism, with individuals targeted for expressing mainstream rightwing views because the definition of neo-nazism has expanded too widely, while the focus on Islamist extremism has been too narrow.

The leaks, from the government-commissioned Prevent review being carried out by Sir William Shawcross, are likely to be deeply controversial. They come days after a mass shooting in Buffalo, New York, where a self-confessed white supremacist shot 11 black and two white victims in what authorities described as a “racially motivated hate crime”.

Sir Peter Fahy, the former police lead for Prevent, said the review extracts suggested Shawcross’s findings were an unwarranted attempt to “politicise counter-terrorism policing” and it was “quite dangerous to play off one ideology against another”.

The draft Shawcross review also claims that:

*  a renewed focus on Islamist extremism is needed, including when individuals do not yet meet the terrorism threshold.

*  individuals have been referred to Prevent, the government’s anti-extremism programme, to access mental health support even when there is no evidence of extremism.

*  some Prevent-funded groups have promoted extremist narratives including support for the Taliban.

The long-delayed review by Shawcross, which was delivered to the Home Office at the end of April, has already drawn criticism from civil society groups, dozens of whom have declined to participate.

Shawcross, a former head of the charity watchdog, has made controversial comments about Islam. In 2012, as a director of the neoconservative thinktank the Henry Jackson Society, he said: “Europe and Islam is one of the greatest, most terrifying problems of our future. I think all European countries have vastly, very quickly growing Islamic populations.”

The number of referrals to Prevent relating to far-right extremism exceeded those for Islamist radicalisation for the first time last year. Referrals for far-right threats from the Prevent programme to Channel, which provides more intensive intervention, had already outstripped Islamist radicalisation since 2020.

In Shawcross’s draft review of the Prevent programme, he argues that its purpose must be refocused and says its first objective, to tackle the causes of radicalisation and respond to the ideological challenge of terrorism, “is not being sufficiently met”.

It argues that the programme must re-engage with individuals who are not yet posing a terror threat but who can “create an environment conducive to terrorism”.

One extract says Prevent has a “double standard when dealing with extreme rightwing and Islamism”. It says the programme has taken an expansive view on rightwing terror, which has “been so broad it has included mildly controversial or provocative forms of mainstream, rightwing-leaning commentary that have no meaningful connection to terrorism or radicalisation”.

However, it says a more hardline approach should be taken towards Islamist extremism, and that the programme has concentrated on proscribed organisations, “ignoring Islamist narratives”.

The draft review is also critical of Prevent-funded civil society organisations and community projects, suggesting funding is misallocated to “generic” projects and few “could be seen to publicly contest extremist discourse”.

It found that some Prevent-funded programmes “have promoted extremist narratives, including statements that appear supportive of the Taliban”. The draft says: “As a core principle, the government must cease to engage with or fund those aligned with extremism.”

Another extract says Prevent is “carrying the weight” for overstretched mental health services and that vulnerable people have been referred in order to access other forms of support even when they do not pose a terror threat.

It is understood that the report has been finalised by Shawcross and his team. It is still to be fact-checked before being subjected to legal checks in case any person or group can claim they have been libelled, which would potentially expose the Home Office, which picked Shawcross for the role despite extensive misgivings, to paying out legal damages.

Fahy, a former chief constable of Greater Manchester police and head of Prevent until 2015, told the Guardian: “There is a danger of policing thought as opposed to the risk of violence. It is not about ideology but about the risk someone will cross into violence.

“It is about threat, risk and harm. We know there has been an increase in far-rightwing extremism in the UK. The worst terrorist attack in Europe was by a rightwing terrorist, Anders Breivik.

“It sounds to me quite dangerous to play off one ideology against another. There is a danger this is an attempt to politicise counter-terrorism policing. How are the police supposed to judge what is mainstream? Police operate on what is the likelihood of this person being drawn into violence, not whether their views are mainstream.”

The draft extracts are also likely to raise eyebrows in the intelligence services. Ken McCallum, the domestic spy agency’s director general, recently warned that extreme rightwing terrorism accounted for one in five of all counter-terrorism investigations, a threat that had “grown and morphed quite substantially over the last five to 10 years”.

A particular problem, he said, was the “high prevalence” of teenagers in rightwing terrorism investigations, which he suggested was because youngsters were being swept up in a “toxic ideology” of “online extremists and echo chambers”.

The Home Office has proscribed a number of far-right groups in recent years, including the neo-Nazi group Sonnenkrieg Division, members of which have been jailed for serious offences. It also recognised the extreme rightwing group System Resistance Network as an alias of the already proscribed organisation National Action.

Prevent came under renewed scrutiny after the murder of the Conservative MP David Amess, who was stabbed to death in his constituency surgery by Ali Harbi Ali, who said he was motivated by Islamist extremism. His murder last year was followed by another Islamist attack on Liverpool women’s hospital.

A Home Office spokesperson said: “Prevent remains a vital tool for early intervention and safeguarding. We will not allow extremists or terrorists to spread hate or sow division, and Prevent remains an important driver to help divert people away from harm.

“The independent review of Prevent, led by William Shawcross, will ensure we continue to improve our response and better protect people from being drawn into poisonous and dangerous ideologies. The report is currently being finalised and once formally received and after full consideration, the report and the government’s response to it will be published.”