Members of the neo-Nazi group National Action (NA) face being arrested and charged under terrorism legislation if they continue to associate with it, after the government passed an order to place it on the official register of outlawed terrorist groups.
The home secretary, Amber Rudd, said on Monday that the group – which idolises Adolf Hitler and says it advocates national socialism – would be proscribed under the powers in the Terrorism Act because of the threat it poses.
The order comes into effect on Friday and effectively bans the group from having any members or organising events.
In a statement exclusively provided to BuzzFeed News, Rudd explained why she had sought to ban the "racist, anti-Semitic and homophobic organisation which stirs up hatred, glorifies violence and promotes a vile ideology".
"National Action is no stranger to violence. The group promoted and encouraged acts of terrorism after Jo Cox’s murder, including a message which contained a photo of killer Thomas Mair with the caption 'don’t let this man’s sacrifice go in vain'. And although based in the UK, members were pictured earlier this year at a German concentration camp, carrying out Nazi salutes," she said.
"Thankfully, extreme right-wing terrorist attacks are rare ... But one attack is one too many and as the senseless and brutal murder of Jo Cox demonstrated, some people are willing to engage in cold-blooded acts to publicise their despicable views. I am absolutely determined that this violence, and the ideologies that underpin it, will be defeated and the perpetrators brought to justice.
"The government is committed to tackling terrorism, in all its guises and regardless what motivates it. And National Action is a group whose views stand in direct contrast to the core values the vast majority of us share.
"Despite its name, the group is determined to divide communities and stir up hatred. Proscribing it will prevent its membership from growing, stop the spread of poisonous propaganda, and protect vulnerable young people at risk of radicalisation from its toxic views.
"I am confident that as parliament debates the banning of this group this week, politicians across all parties will agree that we must condemn those who threaten our way of life. We must not be afraid to categorise these people for what they are: terrorists."
NA is the first far-right group to be sanctioned under the act and the first such group to be proscribed in Britain since Oswald Mosley's British Union of Fascists in 1940.
The Home Office pointed out that Rudd made the decision to proscribe NA before the trial and conviction of Thomas Mair, the white supremacist who murdered MP Jo Cox in June and was jailed for life.
NA's stunts include launching a "whites-only" food bank in Glasgow, draping a swastika flag over a Jewish memorial, and featuring young female members in a competition titled "Young Miss Hitler".
The size of the group's membership is not known – some anti-fascist activists estimate it is no more than 100 – but it typically recruits people in their twenties and is known to have been active on university campuses. NA relentlessly uses Twitter and its own website to spread its propaganda and to organise events.
Anti-fascist campaigners claim that the group rarely appears with more than 30 members at any of its events, and they tend to travel on public transport before changing into their uniforms once they've arrived.
In August 2015, the group was forced to cancel its "White Man March" through Liverpool city centre after clashes with anti-fascist demonstrators in which six people were arrested.
Terrorist groups that pose a threat to others can be "proscribed" under the Terrorism Act 2000. Membership of any proscribed group is illegal under the act and carries a maximum jail term of 10 years.
Some 70 groups are already proscribed, including Islamist groups such as ISIS, in addition to 14 groups based in Northern Ireland that were banned under previous legislation.
The move to proscribe NA comes after a report that about a quarter of extremists who have been referred to the government's anti-radicalisation programme, Channel, are far-right white nationalists.
The programme, along with the counter-terrorism strategy, Prevent, has been more commonly associated with Islamic terrorism in recent years.
Matthew Collins, of the anti-racism group Hope Not Hate, told BuzzFeed News: "We cautiously welcome this but for the last 18 to 24 months it's been quite obvious that what's been missing was police action against National Action.
"We would have rather police would have acted earlier and arrested them for their illegal activities. But we have a ban and the ball is in National Action's court, to see if they come back – obviously we don't agree with their politics, but we'd welcome them to engage legally and lawfully.
"I would say the state has come down on them very late and the policing of the extreme far-right has been ineffectual up until now."
Professor Nigel Copsey, who runs the Centre for Fascist, Anti-Fascist and Post-Fascist Studies at Teesside University, told BuzzFeed News that the Home Office's decision left it open to the criticism that it is overreacting to the threat groups such as NA pose.
"The decision to proscribe National Action is without doubt historically significant. The last time the government banned a far-right group was in 1940. This was in the extenuating circumstances of war when the British Union of Fascists was proscribed as a threat to national security," he said.
"This is not 1940, and National Action are no fifth column, so this decision will clearly give rise to concerns that the Home Office is reacting disproportionately to the nature of the threat.”
Graffiti and stickers in support of the group have appeared in various places across the UK this year.
Racist “White Zone” stickers spotted in Newbury plastered by antisemitic group National Action… https://t.co/V4xODhsavQ
Joshua Bonehill-Paine, the anti-Semitic troll who was last week jailed for racially abusing Luciana Berger, a Jewish MP, praised NA in blog posts and YouTube videos.
Bonehill-Paine wrote in defence of NA activist Garron Helm, who was jailed for sending a racist tweet to Berger in 2014.
The Community Security Trust, a charity that campaigns against anti-Semitism in Britain, said in a statement that it welcomed the move to proscribe NA:
"[We] hope this deters others from joining such a hateful, anti-Semitic, homophobic, xenophobic, and misogynistic organisation. National Action will now join groups including al-Muhajiroun and its various guises, al-Shabaab, Boko Haram and the Hezbollah military wing, who have all been proscribed by the British government.
"National Action proudly proclaims its anti-Semitism. Its members idolise Adolf Hitler and push anti-Semitism, racism, and xenophobia. Their social media, speeches, and recruitment videos are filled with hate and are an incitement to violence."
Also on Monday, prime minister Theresa May announced that an international definition of anti-Semitism would be adopted in the UK.