Threats posed by the far-right are so severe that in some areas they account for more than half of all activity under the government’s flagship counter-terror programme.
It comes after Monday’s attack saw one killed and ten others injured when a van driven into a crowd of worshippers and said he wanted to “kill all Muslims”, according to witnesses.
Police have a man, since named as Darren Osborne, in custody over the attack.
They also show 304 people were detained for terrorism-related offences in the year to March 2017, the highest number for any year since records began in 2001.
What is Channel?
Channel is part of the Prevent anti-terror strategy. According to the government, the programme “is about ensuring that vulnerable children and adults of any faith, ethnicity or background receive support before their vulnerabilities are exploited by those that would want them to embrace terrorism, and before they become involved in criminal terrorist activity.”
The statistics come as people criticise the media for using the term “lone wolf” to describe Osborne, 47, who has been arrested on suspicion of terror offences.
People on Twitter suggested the use of the term reflected a failure to take the threat from the far-right as seriously as the threat from Islamic extremism.
Dr Paul Gill, a terrorism expert at University College London, said: “I can think of plenty of Jihadi cases depicted as lone wolfs in the media. It’s also a term regularly used in jihadi operational documents.
“We shouldn’t be using the term in the first place. It glorifies and depicts these individuals as cunning and smart.
“We should be demystifying the term and negating its use rather than getting distracted by incorrect assertions of who the media applies it to.”
A spokesman for Hope Not Hate, which campaigns against the far-right, said the Home Office figures were not surprising, adding “wider society needs to pay attention to the threat posed by right-wing extremists”.
He added: “The agendas of the Islamist extremists who carried out the Manchester and London Bridge attacks differ little from the far-right extremists who set out to target Muslims.
“Both share a belief that Muslims and non-Muslims cannot live peacefully together and both use the existence of the other to justify their own warped world view.”
The spokesman added HNH called on authorities to do more to tackle people who encourage terror attacks and those who “use social networks to promote their messages of hate, toxifying the atmosphere and stoking the fires of division and intolerance”.
“While the authorities have taken action against extremist groups like National Action and Al-Muhajiroun, more needs to be done against the non-violent extremists who spew hatred and spread poison that inspire others to act,” he added.