The reviewer, the former chairman of the Charity Commission William Shawcross, handed his findings to the government last April but they have still not been published, four years after the probe was commissioned.
Freedom of Information (FOI) requests by campaigners show that Mr Shawcross and the review team met with the former home secretary Priti Patel, other ministers and Home Office officials 13 times between February 2021 and August 2022 – including on five occasions after the report was drafted.
Documents obtained by the charity Rights & Security International (RSI) also revealed emails from July discussing “legal issues” that the Home Office said needed to be resolved before the report was published.
Communications between the government and review team confirmed that Mr Shawcross would respond to Home Office “comments and requests” and potential amendments.
An email from an unknown sender on 13 April said: “The home secretary [then Priti Patel] is concerned by the delay to the review and is starting to come under significant pressure from the Home Affairs committee, amongst others. She asked to see the draft as soon as possible.”
Only a small number of emails were disclosed under FOI, with names, job titles and departments redacted because the Home Office claimed full disclosure would “compromise the health and safety of key officials, thereby prejudicing the UK’s national security objectives”.
RSI is considering launching legal action over the apparent “interference”, which it argues would undermine the review’s independence and thwart its objectives.
It was set up by Theresa May’s government in 2019, following years of accusations that Prevent stigmatised Muslims, and that a widened duty to report suspected extremism was stifling free speech in schools and universities.
RSI has demanded information on why the Home Office was given a draft copy of the report, the nature of amendments and the subjects raised during meetings.
The Independent understands that Ms Patel’s successor Suella Braverman and the communities secretary Michael Gove have subsequently had input on the review, because they now head the departments with responsibility for the Prevent scheme.
RSI said it has “serious concerns about the lawfulness” of the Prevent review, which was originally meant to be published by December 2021.
Sarah St Vincent, the charity’s executive director, said: “Parliament, by law, required an independent review of Prevent. An independent review should be independent.
“If the government has shaped the content, then the review is not independent, and the public and parliament should not be told that it is.”
Carolin Ott, a solicitor from Leigh Day representing RSI, said that the group “considers that the nature of the interactions between the home secretary and the independent reviewer may compromise the review’s ‘independence’” and means it does not meet the conditions set by parliament.
They were set out in the Counter-Terrorism and Border Security Act 2019, which stated: “The secretary of state must make arrangements for an independent review and report on the government strategy for supporting people vulnerable to being drawn into terrorism.”
RSI previously brought legal action that resulted in the departure of the first reviewer appointed, Lord Carlile, after allegations regarding a lack of independence.
The appointment of Mr Shawcross as his successor in 2021 sparked a boycott by charities over comments when he called “Europe and Islam one of the greatest, most terrifying problems of our future”.
Parts of Mr Shawcross’s draft report have already been leaked to the press, sparking controversy with calls for an intensified focus on Islamist extremism despite years of rising threats from the far right and other ideologies.
A legal letter from RSI to the Home Office said the leaked conclusions “appeared to support the secretary of state’s agenda in relation to Prevent and occurred shortly after what appears to be intervention by the Home Office in the substance of the report”.
“A key purpose of the independent review has been to restore trust and confidence in the Prevent strategy,” the letter added. “It is critical for the review to be regarded as neutral so its conclusions will be accepted.”
Since the review was announced, the proportion of Prevent referrals relating to suspected far-right extremism has overtaken those for Islamist extremism, and more than half are now in the “mixed, unstable or unclear ideology” category.
It includes people, often teenagers and those with mental health issues and learning difficulties, who appear to be switching between different ideologies or are obsessed with mass violence or school massacres.
In the year to March 2021, most of the people referred to Prevent were signposted to other public services, such as mental health and education, while a fifth saw no further action and the remainder were considered for ideological mentoring under the Channel programme.
A Home Office spokesperson said: “The Home Office has received a letter regarding Rights and Security International’s concerns surrounding the lawfulness of the Independent Review of Prevent, following an FOI request.
“These concerns are unwarranted and we will be responding directly to this letter in due course.”