Human rights campaigners have threatened the Home Office with legal action over its appointment of Lord Carlile as the independent reviewer of its anti-radicalisation programme Prevent.

The peer’s appointment, announced this month, was met with criticism from human rights and civil liberties groups, citing his previous on-record support for the Prevent programme.

Carlile has admitted to parliament that he “may be somewhat biased towards” Prevent and declared his “considered and strong support” for the programme.

However, in an interview with BBC Newsnight, the peer sought to reassure critics, claiming that “everything is up for discussion, including scrapping” the programme.

The review was announced following years of mounting criticism of Prevent, which has become a toxic brand for many within Muslim communities, with some viewing it as a state tool for spying on them.

The human rights charity Rights Watch (UK) has taken the first step in legal action against the government to challenge Carlile’s appointment.

The group – which works to ensure measures taken by the UK government in pursuit of national security are compliant with human rights and international law – alleges that, in leading the review, Carlile cannot be independent. The peer oversaw the government’s first review of Prevent in 2011 and has previously been a member of the Prevent oversight board.

Yasmine Ahmed, the director of Rights Watch (UK), said: “The long overdue independent review of Prevent, a key pillar of the UK’s counter-terrorism strategy, is in danger of becoming a whitewash with the announcement of Lord Carlile of Berriew as the independent reviewer.

“It beggars belief that the government could consider Lord Carlile as an appropriate independent candidate for this important role.”

She added: “This appointment fundamentally undermines the credibility of the review and risks derailing the entire process, and we are prepared to challenge the decision in court.”

Rights Watch (UK) has sent a letter before action via its lawyers Leigh Day – the first step in judicial review proceedings – to the Home Office and government legal service outlining its concerns. The government has a period of time to respond. If the response is considered inadequate then the group can issue legal proceedings.

The Prevent strategy includes a statutory duty on specified authorities, including those working in schools, and health and social services, ​to report any signs of “extremism” and ​to ​make referrals to the government’s counter-radicalisation Channel programme. In 2017-18, 7,318 individuals were referred to Prevent.

Carolin Ott from Leigh Day, the law firm representing Rights Watch (UK), said: “Our client is quite rightly concerned that the government’s appointment for independent reviewer of Prevent seems to be anything but independent.

“Not only did Lord Carlile oversee the 2011 review of Prevent, but he also held a role on the Prevent oversight board, an internal oversight body charged with ‘driving delivery’ of Prevent.

“Of further concern is the fact that he is on the public record expressing his support for Prevent, and argued in parliament against the very establishment of the review, even conceding that he is ‘biased towards’ Prevent. It is very difficult to see how he can be described as independent, and our client argues that it is therefore inappropriate for him to carry out the review of this controversial strategy.”