An upcoming review of the Prevent anti-terrorism programme is an opportunity for long-standing critics to “stand up and be counted”, a chief constable has said.

Simon Cole, the national policing lead for the scheme, challenged those who have complained of a “lack of independent analysis and oversight” to use their chance to influence policy and suggest improvements.

“Failure to do so would demonstrate that all they ever had was arguments based on inaccuracies or myth, and no real ideas about how to tackle radicalisation among the young and the vulnerable,” he said.

Having previously rejected calls for the move, the government announced last month that Prevent would be subject to an independent review.

Cole’s remarks chime with those of the security minister, Ben Wallace, who said when announcing the review that it “should expect those critics of Prevent, who often use distortions and spin, to produce solid evidence of their allegations”.

With an annual budget of about £40m, Prevent aims to stop people becoming terrorists or supporting terrorism.

The Prevent strategy includes a statutory duty for schools, NHS trusts, prisons and local authorities to report concerns about people who may be at risk of turning to extremism.

While police and ministers have emphasised it is a crucial plank of anti-terrorism efforts, the scheme has repeatedly come under fire, with critics labelling it heavy-handed and toxic.

In a blog posted on the National Police Chiefs’ Council website, Cole, the head of Leicestershire police, welcomed the review.

“We now have an opportunity to demonstrate what the programme can offer, and for unbiased experts to weigh that up against the criticisms, misleading rhetoric and false perceptions which have plagued the scheme.

“An independent review should also have been welcome news for those who have spent so long criticising the programme, because they will now have an opportunity to air their concerns and suggest how changes to Prevent might improve the way we tackle radicalisation and extremism in the UK.

“Now is the time for hard fact, not twisted fiction. It is the time for anyone with genuine concerns or policy ideas to stand up and be counted, or else never be able to fairly criticise Prevent again.”

He said prevention has never been more important, with police and security services running more than 700 live counter-terrorism investigations.

“Prevent is a crucial part of the battle against terrorists, and hopefully this review can be the next stage in our development of the work, our building of the evidence base, and us making Prevent more inclusive,” Cole wrote.

He said he expected the review to reflect on the growth of far-right referrals to Prevent, which increased by more than a third in 2017-18, to 1,312. Referrals over Islamist extremism concerns fell by 14%, to 3,197.

In total 7,318 individuals were flagged up to Prevent in the 12 months to March last year, including more than 2,000 aged under 15.

Anyone concerned that someone they know might be at risk can refer them to Prevent. In most cases, referrals are found to require no further action or are passed to other services.

When authorities conclude there is a danger the person could be drawn into terrorism, they can be supported through a scheme known as Channel. Engagement is voluntary and it is not a criminal sanction.