The man behind a plot to murder MP Rosie Cooper belonged to a banned far-right group which aimed to "wipe out" non-whites "by any means necessary", a whistleblower told jurors.
Jack Renshaw, 23, has admitted preparing acts of terrorism by buying a large knife to kill his local MP as well as threatening to kill a police officer he had a grudge against.
In July last year, he was allegedly given the blessing of National Action leader Christopher Lythgoe, 32, who told him not to "f*** it up".
Renshaw's murderous plan was scuppered by disillusioned former National Action member Robbie Mullen, who reported it to campaigning charity Hope Not Hate.
Lythgoe denies giving Renshaw permission to murder the West Lancashire MP on behalf of National Action.
The pair, along with four other men, have denied membership of National Action after it was banned in December 2016 for supporting the murder of MP Jo Cox.
Giving evidence at the Old Bailey, Mr Mullen, from Widnes, Cheshire, said he joined National Action in 2015 after becoming interested in the extreme far right at the age of 18 and finding out about it from the internet.
He told jurors that the group stood for "the free white man" and was against "everything - Jews, blacks, Asians, every non-white".
Prosecutor Duncan Atkinson QC asked what National Action hoped to achieve.
Mr Mullen replied: "Wipe them out by any means necessary. War, anything."
He implicated all the defendants in the extreme right-wing organisation, saying they continued to be involved with it after the ban.
Asked why he had first contacted Hope Not Hate in April last year, he said: "I honestly think to get out of National Action."
Renshaw, from Skelmersdale, Lancashire and Lythgoe, from Warrington, are on trial with Garron Helm, 24, of Seaforth, Merseyside, Matthew Hankinson, 24, of Newton-le-Willows, Merseyside, Andrew Clarke, 33, and Michal Trubini, 35, both of Warrington.
Earlier, jurors were shown National Action propaganda videos of demonstrations across England and Scotland in which men wore skull masks, waved banners and made Nazi salutes.
Some of the defendants, including Renshaw, were identified in the footage and Lythgoe and Hankinson also featured in a Mixed Martial Arts training video, the court heard.
Police Constable Matthew Fletcher explained the history of the self-styled "youth movement" which was described as "virulently racist".
He told how it was based on neo-Nazi ideology and hatred of members of Jewish, gay and ethnic minority communities.
It was banned after promoting the murder of Batley and Spen MP Ms Cox in tweets which called for her killer Thomas Mair's "sacrifice" not to be in vain.
Pc Fletcher told how it was founded in late 2013 by university students Alex Davies and Benjamin Raymond.
It targeted young men in their twenties and represented a neo-Nazi British national socialism, the court heard.
Pc Fletcher said their black and white logo was similar to that of the Adolf Hitler's brown shirts.
Recruitment was via the internet and through the distribution of leaflets at demonstrations, Pc Fletcher said.
Asked if it was a large organisation, Pc Fletcher said in 2014 numbers were "low" but it "succeeded in its propaganda message and recruitment continued".
National Action used stickers around universities and "flash demonstrations" in towns and cities.
Founder Mr Davies was removed from Warwick University due to the sticker propaganda campaign there, jurors heard.
Stunts by activists included the desecration of the statue of Nelson Mandela in Parliament Square, placing a banana in his hand.
The Metropolitan Police officer, tasked with tackling domestic extremism, said National Action was not really in favour of British democracy.
Mr Atkinson asked: "What kind of war was National Action interested in?"
Pc Fletcher said: "Part of white supremacy is preparation for the race war in their eyes, in their ideology."