The number of right-wing extremists behind bars for terrorism offences has doubled in two years.
There were up to 41 in custody in the year to the end of December, up from 21 in 2017 and four in 2014.
A report from the Home Office said: “The proportion of prisoners holding far-right ideologies has increased steadily over the past three years.”
The increase has been spurred by Islamophobia, which surged in the wake of Islamic State attacks.
It comes after MPs backed a ban on right-wing groups Sonnenkrieg Division and System Resistance Network.
Overall there were 231 people in jail for terrorism-related offences, with 77% holding Islamist views.
