The home secretary, Amber Rudd, has warned that far-right groups are becoming "increasingly sophisticated" online and that more and more people are now being identified as being at risk of "extreme right-wing radicalisation".
Speaking at the Jewish News/BICOM conference in parliament on Wednesday, Rudd talked about the "shocking, senseless" murder of Jo Cox "in her own constituency by the far-right extremist Thomas Mair".
She said: "We know that far-right and extreme right-wing groups are becoming increasingly sophisticated in the use of social media for promotion and recruitment.
"We’re seeing currently that around a quarter of the cases getting support through Channel, part of our Prevent programme, are for extreme right-wing radicalisation. I am absolutely determined that we challenge extremism in all its forms and the terrible damages it has on individuals and families."
Channel is a Home Office initiative that aims to find people who are at risk of radicalisation and provide support at an early stage. It involves a number of different organisations, including local authorities, border forces, community services, and others.
Earlier at the conference, shadow international trade and climate change minister Barry Gardiner drew mixed reactions from the crowd when talking about Labour's controversies around anti-Semitism.
Discussing the media coverage of the party's internal battles, Gardiner said he found it "absolutely extraordinary" how Labour was "taken to task by the media in quite the way it was, at a time where the Conservative party had just run a mayoral election campaign which was the most racist campaign that I can ever remember".
"I did think that there were certain elements of the press that wanted to shift the focus on to Labour," he said, though adding that "it’s not to say that there weren’t problems, and not to say that they didn’t need to be dealt with".
Gardiner attended the event as a replacement for shadow foreign secretary Emily Thornberry, who was initially scheduled to speak but had to fly to Cuba for Fidel Castro's funeral.