The government’s anti-radicalisation Prevent strategy is to be independently reviewed after ministers gave into longstanding pressure to address concerns over its impact on communities.

The security minister, Ben Wallace, announced the review in the House of Commons but threw down the gauntlet to critics of the strategy to produce “solid evidence of their allegations”, accusing them of using “distortion and spin”.

The move was announced after the government accepted an amendment to the counter-terrorism and border security bill passing through parliament.

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.

Civil liberties and human rights organisations such as Amnesty International have been calling for an independent review of Prevent for some time, claiming it fosters discrimination against people of Muslim faith or background and inhibits legitimate expression.

Proponents of the strategy say statistics prove that it does not target one community in particular and has successfully diverted vulnerable individuals from being radicalised and in turn from becoming terrorists.

Wallace said: “I have decided that the time is now right to initiate a review of Prevent. Communities across the country have got behind the policy and are contributing to it because they want, as we do, their own young people to be protected from grooming and exploitation by terrorists.

“Over the last two years the Home Office has built on the solid work of Prevent by releasing annual statistics. They clearly show that Prevent is not about singling out any particular group or ideology but is similar to other forms of safeguarding carried out every day by social workers, teachers and police.

“I am proud we have helped divert hundreds of people away from posing a real threat and put them back on the path of living a fulfilling, law-abiding life.”

The Home Office said that since 2012 more than 1,200 people had been supported by Channel, a mentoring programme that is part of the Prevent strategy. Of the 394 people who received Channel support in 2017/18, 179 (45%) had been referred for concerns related to Islamist extremism and 174 (44%) for concerns related to rightwing extremism.

The review will begin within six months of the legislation coming into force and there will be a requirement to report back to parliament within 18 months.

Muslims groups have made it clear they have little or no confidence in Prevent, which over time has faced claims that it is more concerned with gathering intelligence than supporting communities.

Harun Khan, the secretary general of the Muslim Council of Britain, said on Tuesday: “We welcome the government’s support for a review. However, those tasked with its implementation must have the independence, credibility and trust required to deliver it.”

Critics have called Prevent a “toxic brand” and argue that at its heart is an ideological purity test that means western foreign policy cannot be criticised and that the government is prepared to work only with those who do not challenge it.

But there is unanimity in counter-terrorism circles that it is needed to limit the threat Britain faces from Islamist terrorism as well as the rising menace of extreme rightwing terrorism.

On Wednesday the head of counter-terrorism policing, Neil Basu, revealed that 18 plots to causes mass murder on British soil had been thwarted since March 2017, of which 14 were Islamist and four rightwing.

Basu said that one in five pieces of information provided by the public had helped police and MI5 move closer to those plotting attacks, but the amount of information coming in had more than halved compared with 2017, from 31,000 pieces of information to 13,000.

He said: “It’s not so much the volume of threat but a shift in the threat to the young and the malleable, even the mentally ill who are being affected by what they are seeing, and they are taking that and then using very low-sophistication measures, things that everyone can get access to – a knife or a vehicle – and making an attack. And those are the kind of things that worry us most: they are the hardest to see and they are the hardest to stop.”

A new advertising campaign starts soon in cinemas, urging people to report any concerns.