A whistle-blower who helped scupper a neo-Nazi plot to murder an MP has been warned by police he is at risk of being killed.
Robbie Mullen reported a threat against Labour MP Rosie Cooper to Hope Not Hate after 23-year-old Jack Renshaw, from Blackpool, spoke of his plan in July 2017.
Renshaw admitted making preparations to kill West Lancashire representative Ms Cooper - including purchasing a 19-inch (48cm) Gladius knife - and will be sentenced next month.
Mr Mullen, 25, has been subject of five Osman warnings, where police have had intelligence about a threat to life but not enough to justify arresting the potential offender.
He told The Observer his decision to leak information about National Action to campaign group Hope Not Hate has "totally ruined" his life.
He said: "The police have offered me witness protection after each death threat but each time I've turned it down because I want the option to go back home.
"They would have made me start again, changed my name."
National Action was the first extreme right-wing group to be proscribed by the Government since the Second World War.
In December 2016, it was banned by the then home secretary Amber Rudd over its support for the murder of Batley and Spen MP Jo Cox.
Group leader Christopher Lythgoe reacted to the news by telling members that they would "just shed one skin for another".
By July 2017, Renshaw was on police bail for making hate speeches and under investigation for child sex offences.
He decided on "suicide by cop" rather than face a seven-year stretch in prison.
He bought a large machete to take revenge on a female investigating officer and kill his local MP.
Renshaw unveiled his plan at the Friar Penketh pub in Warrington on July 1 2017 with Mr Mullen going on to inform Hope Not Hate's head of intelligence.
He told the Observer: "I didn't want to move or leave my job but had to drop everything and everyone I knew. It has totally ruined my life."
Renshaw, originally from Skelmersdale, moved to Blackpool when he was 15. He failed in a bid to become a councillor in the resort.