WARNING: Some readers may find language within this article offensive.

Video report by ITV News Security Editor Rohit Kachroo

Article by Becky Kelly, Specialist Producer, ITV News UK Bureau

Former members of Britain’s first white supremacist terror group are still meeting in secret, despite being banned by the Government, an undercover investigation by ITV News can exclusively reveal.

National Action celebrated the death of MP Jo Cox before the group was banned by the Home Office in December.

The ban makes it a terrorism offence for the group to exist or meet, with a jail term of up to 10 years if convicted.

But undercover filming by ITV News caught individuals with links to the banned group together at a training camp for far-right sympathisers in the Peak District earlier this month.

The weekend billed itself as a “survival camp” with boxing and street fighting sessions, as well as how to deal with a knife attack.

Speeches were also given by organiser Larry Nunn on creating an “organised white society”.

Garron Helm, a prominent former member of National Action, was secretly filmed discussing the murder of Mrs Cox within an hour of arriving at the camp.

He claimed police used the MP’s death to pursue National Action.

“It’s not our fault she was killed,” he said. “I mean, she did have it coming.”

Garron Helm was jailed for sending an antisemitic tweet to Jewish MP Luciana Berger Credit: ITV News

The 23-year-old added: “You see a lot of the lads are bitter over it. I mean some of the areas they are growing up in are so rough and so infested with you know, ethnics, that they’ve literally got no tolerance for people anymore they believe to be committing treason.”

National Action adopted the words of Mrs Cox’s killer, “death to traitors”, as its motto and Helm was filmed saying: “I do think if you’re committing an act of treason against, you know, your own ethnic group then by right you should be put to death.”

Brendan Cox, Mrs Cox's widower, told ITV News that the rise of the far right is something "we should all take more seriously".

“Their attempts to undermine our country’s values of decency and inclusion will not succeed if we hold together against their hatred," he said.

"Jo dedicated her life to bringing people together and building stronger communities. Her values reflected the best of what it means to be British and the way the nation as a whole responded to her murder is evidence of that."

Helm, from Liverpool, was jailed in 2014 for sending an antisemitic tweet to Jewish MP Luciana Berger.

The offending tweet showed a Nazi-style yellow star superimposed on Mrs Berger’s face with the words “#Hitler was right”.

Jo Cox MP was killed by neo-Nazi Thomas Mair in June 2016.

Our undercover reporter and others at the camp were sat chatting on sofas when Helm mentioned his conviction.

“I had that argument with that Luciana Berger on Twitter and I just actually said ‘you’re just a Jew’,” Helm said.

“The old bill turned up at the door and not even bobbies as well, CID (Criminal Investigation Department). Some of them pulled me in and ‘bang’! No previous convictions, no history with the police but you’re going right to prison."

During our filming, Helm revealed UK security services had already warned him about holding National Action meetings.

“They basically said: ‘Listen, if we see three or four of you meeting up and we deem it to be an NA meeting, rather than friends meeting, then we will just come after you with everything we’ve got’.”

Also at the camp was a man who calls himself James Mac, who was photographed last year at National Action demonstrations.

James Mac at a National Action demonstration in March 2015. Credit: Hope Not Hate

Mac, who said National Action was "just a name", made anti-Jewish comments during the meeting, saying: “They carry on like somebody’s died. You know like if a family member died and somebody got off, they carry on like that, just about somebody who bad-mouthed them. This is the way these Jews carry on.”

During the meeting, Mac promoted his white separatist religion “Creativity” to our reporter, which he described as “what’s good for white people”.

The leaflet for “Creativity” includes a photo of a group of children doing the Nazi “Sieg Heil” salute.

Four of the 15 people who attended the three-day camp have links with National Action.

Over the past four months, ITV News has been following the movements of the supposedly disbanded terror group.

In February, we covertly filmed at the London Forum, a far-right conference.

A few weeks later our investigation took us to Rotherham, where we suspected National Action members had joined forces with another far-right group to prevent detection.

Organiser Larry Nunn gave a speech on creating an 'organised white society'. Credit: ITV News

Far from disbanding, National Action's former members appear to be trying to work around the ban imposed by the Home Secretary.

Matthew Collins, from Hope Not Hate, told ITV News that the group has always suspected National Action was using new tactics and had not ceased to exist, something he said was a "grave concern".

He said: "They are still incredibly active and still very much involved in extremist politics in this country."

Mr Collins said those involved in National Action still pose a threat and that the Home Office proscription was not working, as the group could still operate under a different name.

"Whether they use the name National Action or not, we believe their activities could encourage others to engage in terrorist acts," he said.

Our undercover investigation shows that some are still active and spreading white supremacist views.

How the Government and counter-terrorism police will respond remains to be seen.

A Home Office spokesperson said: "National Action is a racist, antisemitic and homophobic organisation which stirs up hatred, glorifies violence and promotes a vile ideology. It has absolutely no place in our society.

“The organisation was proscribed in December, as it was assessed to be 'concerned in terrorism'. As a result, being a member – or inviting support for – National Action is a criminal offence, carrying a sentence of up to ten years imprisonment.

“Decisions about whether to prosecute are taken by the police and Crown Prosecution Service.”