Thousands of children and teenagers have been flagged up to authorities over terror concerns, official figures reveal.

In the year to March, 2,009 under-15s were referred to the Government’s Prevent programme, including 297 girls.

The number in the youngest age group increased by a fifth on the previous year, while over half of those reported for possible de-radicalisation interventions in 2017/18 were 20 or under.

In total there were 7,318 referrals to Prevent in 2017/18 – up by 20% on 2016/17.

Officials suggested last year’s terrorist attacks are likely to have been a factor in the rise.

The Home Office statistics revealed a jump of more than a third in the number of referrals sparked by concerns about right-wing extremism.

While Islamist concerns accounted for a larger proportion of referrals, the number in the category fell by 14% year-on-year.

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

Anyone concerned that someone they know might be at risk can refer them.

When authorities conclude there is a risk that 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.

The latest figures show that, of those referred to Prevent in 2017/18:

– 3,096 (42%) left the process requiring no further action
– 2,902 (40%) left the process and were signposted to alternative services
– 1,314 (18%) were deemed suitable, through preliminary assessment, to be discussed at a Channel panel

Six referrals were “open” at the time the information was gathered.

Of the cases examined by Channel, 394 subsequently received support through the scheme, including 114 aged under 15.

The Home Office said that, of those who have left the Channel process, more than four in five did so with “no further terrorism-related concerns”.

There was a 36% increase in the number of referrals to Prevent for concerns related to right-wing extremism, rising from 968 in 2016/17 to 1,312 in the latest year.

Referrals over Islamist extremism concerns fell from 3,704 to 3,197.

For the first time a similar number of individuals received Channel support for concerns relating to Islamist and right-wing extremism, the report said.

In 2015, public bodies were placed under a statutory duty to stop people being drawn into terrorism.

The sectors accounting for the highest number of Prevent referrals in 2017/18 were education (2,462) and the police (2,364).

Regionally, nearly a quarter (23%) of those referred were from London, followed by the North East (17%).

While police and ministers say it forms a crucial plank of anti-terror efforts, Prevent has repeatedly come under fire, with critics labelling it heavy-handed and “toxic”.

Responding to the latest figures, shadow home secretary Diane Abbott said: “Literally thousands of people are being referred to the programme but the overwhelming majority do not require any anti-terrorism procedures at all.”

Earlier this month, Home Secretary Sajid Javid issued a staunch defence of the scheme, insisting it plays a part in keeping Britain safe by helping stop young people being preyed on by extremists and turning around hundreds of lives.

Last year it emerged that in one case, a nine-year-old boy was helped by the programme after standing up in class and declaring that he supported Islamic State.

Fresh questions were raised about Prevent after a wave of terror attacks hit Britain last year.

Last month the Intelligence and Security Committee said Manchester bomber Salman Abedi should have been considered for a Prevent referral after his closure as an MI5 “subject of interest” in 2014.

Parsons Green attacker Ahmed Hassan was discussed at nine Channel panels, the last of which took place 10 days before he planted a bomb on a Tube train.

Security minister Ben Wallace said: “Prevent plays a vital role in stopping vulnerable people being drawn into all forms of terrorism and safeguarding is at the heart of it.

“The figures released today show Prevent is tackling the threat from radicalisation wherever it is found, including from the rise in the right-wing extremism.”

Chief Constable Simon Cole, National Police Chiefs’ Council lead for Prevent, said: “The Prevent safeguarding duty is now well embedded within statutory bodies who are alert to all forms of extremism.

“We have become more sophisticated in identifying people where ideology isn’t the primary driver of a person’s vulnerability and complex needs.

“However, all agencies need to work with communities to improve understanding of what Prevent is and how it can stop vulnerable people being drawn into terrorist activity.

“At a time when we are dealing with a record number of CT (counter-terrorism) investigations, it is far better to stop a loved one getting drawn into criminal activity in the first place.”