A neo-Nazi could be facing a life behind bars for plotting the murder of Labour MP Rosie Cooper while being investigated for grooming young boys for sex.

Jack Renshaw, 23, bought a 19in (48cm) Gladius knife to kill the West Lancashire MP and exact revenge on a female police officer who interviewed him, the Old Bailey heard.

The plan was scuppered by whistle-blower Robbie Mullen, who was at a meeting in a pub when Renshaw announced that he was going to kill Ms Cooper in July 2017.

Jack Renshaw plotted to kill MP Rosie Cooper (Steve Parsons/PA)

It came just a year after Labour MP Jo Cox was stabbed and shot by a fellow far-right extremist, Thomas Mair.

Renshaw, from Skelmersdale, Lancashire, had admitted making preparations to kill his local MP and making a threat to kill police officer Victoria Henderson.

But he denied membership of banned extreme right-wing group National Action along with Andrew Clarke, 34, and Michal Trubini, 36, from Warrington.

A jury at his retrial was discharged, having failed to reach verdicts after more than 48 hours of deliberations and prosecutor Duncan Atkinson QC said he could not seek a third trial.

It can be reported today that Renshaw is a convicted paedophile who was jailed last June for 16 months after he groomed two underage boys online.

Jurors at Preston Crown Court found him guilty of four counts of inciting a child to engage in sexual activity.

He also received a three-year prison sentence two months earlier when he was found guilty of stirring up racial hatred after he called for the genocide of Jewish people.

National Action leader Christopher Lythgoe, 32, of Warrington, and his right-hand man Matthew Hankinson, 24, from Merseyside, who were present when Renshaw outlined his plans, were convicted of membership last year.

Adam Thomas and his partner Claudia Patatas (West Midlands Police/PA)

National Action is 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 Ms Cox.

Lythgoe reacted to the news by telling members that they would “just shed one skin for another”.

The North West contingent continued to meet in pubs and train together at a new mixed martial arts gym in Warrington, it was alleged.

Meanwhile, disillusioned Mr Mullen, 25, began leaking information about National Action to campaign group Hope Not Hate.

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 to Clarke, Hankinson, Lythgoe and Mr Mullen.

Earlier that day, he had met convicted National Action members Darren Fletcher, 28, Adam Thomas, 22, and his partner Claudia Patatas, 39, in Liverpool.

After the pub meeting, Mr Mullen, from Widnes, Cheshire, reported the threat to Hope Not Hate and Renshaw was arrested.

Mr Mullen, who was granted immunity from prosecution, told jurors: “He said he was going to kill his local MP, Rosie Cooper. I said ‘Are you sure?’ and he said ‘Yeah’.

“He said he would kill her, then try to take some hostages to lure the police officer that was investigating him to try to kill her because she was the reason behind it all.

“He said his mind was made up. He had bought a machete.”

Renshaw said he would wear a fake suicide vest so he would be killed by police, Mr Mullen added.

The defendant declined to give evidence in his retrial, but in his first trial last year explained his reasons for targeting Ms Cooper.

He said: “I wanted to send a message to the state that if you beat a dog long enough it bites – she just happened to be my local MP.”

Giving evidence, warehouse worker Clarke said: “National Action was immature. I was tired of it. I was thankful for the ban.”

He told jurors a Swastika bookmark found in his sister’s loft was “a joke” and he only went to the Friar Penketh on July 1 on a “whim”.

He said: “Renshaw said something about an MP when I was drunk but I do not remember what he said. Whatever Renshaw was doing I heard it but I did not really pay attention because I was drunk.”

Office worker Trubini, who qualified as a teacher in Slovakia, admitted a shared ideology about white nationalism and opposition to multiculturalism.

But he said: “I would not jeopardise my job to be a member of a group that had no real impact.”

Trubini insisted he was “politically naive” and having tried to read Mein Kampf, found it “boring and badly written”.

As she discharged the jury from returning verdicts, Mrs Justice McGowan said: “You have obviously worked very hard. You have obviously been very diligent. You have obviously worked your way through all the material so we understand and respect the decision you have made.”

She remanded Renshaw into custody to be sentenced on May 17.

Hope not hate chief executive Nick Lowles praised the bravery of Mr Mullen in foiling the plot but criticised police for being “too slow” to act.

He said: “We all owe a great debt of gratitude to Robbie Mullen, our source inside this Nazi gang, for his bravery.

“National Action was part a new, more extreme breed of neo-Nazis that vilified Jews, celebrated and encouraged violence and lauded Hitler. They wanted to ignite a race war in Britain.

“While we welcome the various prosecutions which have taken place, the authorities and police have been too slow to act and missed too many warning signs about the changing nature of the far-right terror threat.

“The Christchurch terrorist attack shows that there is a global network of far-right activists who are inspiring each other to launch violent attacks. This is no time for complacency about the threat we face from far-right terrorism.”

Matthew Collins, Hope not Hate’s head of intelligence, said: “We continually warned that National Action had not stopped recruiting and training after its ban in December 2016 and we were proven right when Robbie Mullen first came to us in April 2017.

“At the time, police didn’t seem to have any idea that the group was still active, despite its ban. I can only pay tribute to Robbie’s persistence, which helped prevent the murder of an MP.

Mr Mullen thanked the organisation, saying: “By reporting Jack Renshaw’s murder plot and giving evidence in this court my life has changed. I had to walk out of my job, I was forced to move home and I have to live with a target on my back.

“But I know I had no other choice. Jack Renshaw was days away from trying to kill an MP, Rosie Cooper.

“I now want to get on with the rest of my life – I hope that in doing so, and rebuilding my life, I can encourage others to take a different path than I did.”

Ruth Smeeth MP, who warned Ms Cooper after learning of the danger, said it had been a “truly shocking” case.

She said: “Two years after the devastating murder of my colleague Jo Cox, we narrowly averted what could have been another appalling crime.

“I cannot overstate Hope not Hate’s role and what might have happened had Robbie Mullen not been able to report Jack Renshaw’s plans. We all owe Robbie a huge debt of gratitude for what he did.”