Much of Kevin Wilshaw's life has been defined by a belief in white supremacy.

Over the past 44 years, between the ages of 14 and 58, he has worked with UK far-right extremist groups peddling Neo-Nazi ideology.

His actions ranged from mundane "leafletting" to "occasionally getting involved in political violence".

Mr Wilshaw was still an active member of a far-right political party earlier this year, even speaking at public events.

But now he claims to have put his days as a Mein Kampf-reading racist behind him to address the contradictions that have plagued him in private.

Mr Wilshaw is not only gay, but has Jewish blood through his mother.

Kevin Wilshaw at a demonstration in 1983. ( Supplied )

"I tended to compartmentalise things," he said.

"I put my political life in one section and my normal life in the other."

Mr Wilshaw was recently arrested on online abuse charges — the second time he has been arrested.

He said he quit the movement for good after being attacked for his sexuality.

"I've had threats from people on the far left who think I'm insincere but especially people on the far right who think I'm a traitor," he said.

"I can't win".

Help came from a former Neo-Nazi

Support has come from a fellow former extremist.

Matthew Collins was once an organiser for a far-right group and knew Neo-Nazis "who were involved in extreme violence … and did kill people".

He turned informant and fled to Australia between 1993 and 2003 for his own safety.

Kevin Wilshaw and Matthew Collins. ( ABC News: James Glenday )

Now he works for anti-fascist campaign group Hope Not Hate, researching the state of the UK far right and trying to convince people to leave the movement.

"Is Kevin cured? No, I don't think so … but Kevin's on the way," Mr Collins said.

"The work with Kevin is about socialisation. He wants to walk down the streets with another man and maybe hold hands.

"Our thing is to mix him in with regular normal people, drinking beer without dressing up like a [WWII German] tank commander, [and] having nice pictures on your living room wall, not pictures of Hitler."

British far right declining, desperate and more dangerous

The latest figures show right-wing extremism only makes up about 10 per cent of cases dealt with by the UK Government's main deradicalisation program.

Anti-fascist campaigners believe the country's extreme far right has declined significantly in recent years, perhaps to its lowest point in two decades, and some commentators have dismissed the remaining members as weird, uneducated white men with uniform fetishes.

But the murder of Labour MP Jo Cox by a Nazi-sympathiser in the days before last year's Brexit referendum showed the danger posed by elements of the movement has not passed.

Kevin Wilshaw at a demonstration in 2014. ( Supplied )

Since then, three far-right groups have been banned by the UK Government and two people have been charged over a plot to kill another politician.

"We are very concerned by the number of the arrests and the nature of the arrests", Mr Collins said, when asked about the most extreme end of the movement.

"What we are looking at are groups that look like terrorists, talk like terrorists, act like terrorists and our belief for the last 18-months to two years is that they will eventually become terrorists."

Life-long Neo-Nazi now wants to damage former friends

After wasting a large part of his life spouting hatred, Mr Wilshaw claims he now wants to apologise and make amends.

He hopes he can encourage others to quit the movement and damage the anti-Semitic, racist extremists he called friends for so long.

"A lot of people, a lot of Israeli citizens won't see that as adequate," he said.

"But that's all I can offer."