The UK’s most senior counter-terrorism officer has revealed that the number of attacks foiled since the Westminster atrocity has risen to 22, with seven relating to suspected far-right terror.

Speaking at a conference in Israel, assistant commissioner Neil Basu disclosed the updated figure as he laid out the law enforcement case in support of the government’s divisive anti-radicalisation strategy, Prevent.

He said the number of foiled terrorist plots since the March 2017 attack by Khalid Masood on Westminster Bridge, in which five people died including a police officer, had risen from 19 to 22.

Basu urged Lord Carlile – whose appointment as independent reviewer of Prevent has itself been met with controversy – to ignore “malign detractors” of the programme and advocated a public health approach.

“Rather than just treat the symptoms of terrorism we must treat the causes. Prevent – which offers a bespoke programme of support for vulnerable individuals – is the closest thing to a public health solution we have,” he said.

“Evidence indicates people with extremist views are more likely to be moved to violence when they feel excluded. We need to help people who see their position in society as hopeless to find hope – help them find a ‘family’ that believes in society, not a gang that wants to tear it apart.”

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.

Basu, the head of the national counter-terrorism policing network, conceded that the upcoming review would uncover shortcomings in the strategy.

“Critics are right to challenge ambiguity in the programme. It lacks clarity about thresholds for intervention – where safeguarding the vulnerable stops and pursuing a criminal starts,” added Basu.

“These are issues I accept and will work with our new independent reviewer and critical friends to address. But I won’t give ground to critics whose agenda is to discredit Prevent to suit their own ends. No one who has challenged Prevent to date has had a better idea.”

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

In a bid to reassure critics who accused him of being biased in favour of Prevent, Carlile said that “nothing would be off the table” during his review, which would take place next year, including scrapping the programme.

Brandon Lewis, the security minister, said: “We have seen how Prevent has supported many vulnerable people, stopping them from hurting others and themselves, and helping them turn their lives around.

“Since 2012, over 1,700 people have received tailored support through our Channel programme, with the vast majority leaving with no further CT [counter-terrorism] concerns.

“We know Prevent works best when delivered in partnership with communities which is why we support community groups to deliver projects against all forms of radicalisation.

“Last year 181 community projects were delivered, reaching over 88,000 participants. More than half of these were delivered in schools, aimed at increasing young people’s resilience to terrorist and extremist ideologies.”