A neo-Nazi who admitted plotting the murder of the Labour MP Rosie Cooper will not face a second retrial for membership of the banned group National Action.

Jack Renshaw, 23, bought a 48cm (19in) gladius knife to kill the West Lancashire MP and a female police officer against whom he had a grudge, the Old Bailey heard. The plan was scuppered by Robbie Mullen, who was at a meeting in a pub when Renshaw announced he was going to kill Cooper.

It happened just a year after the Labour MP Jo Cox was fatally stabbed and shot by the far-right extremist Thomas Mair.

Renshaw, from Skelmersdale, Lancashire, had admitted making preparations to kill his local MP in 2017 and making a threat to kill the police officer Victoria Henderson, who was investigating him.

However, he denied membership of the banned extreme rightwing group National Action, as did Andrew Clarke, 34, and Michael Trubini, 36, from Warrington.

The jury deliberated for more than 48 hours but were unable to reach majority verdicts on any of the defendants following the retrial. The judge, Mrs Justice McGowan, discharged the jury after being told there was no prospect of them reaching verdicts if given more time.

The prosecutor, Duncan Atkinson QC, told the court that after careful consideration a decision had been made not to seek a further retrial.

It can now be reported that Renshaw is a convicted paedophile who was jailed for 16 months last June 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.

The court heard how the convicted National Action leader, Christopher Lythgoe, 32, of Warrington, and his right-hand man Matthew Hankinson, 24, from Merseyside, were present when Renshaw outlined his plans.

National Action is the first extreme rightwing group to be proscribed by the government since the second world war. It was banned in December 2016 by the then home secretary, Amber Rudd, over its support of Cox’s murder.

Lythgoe reacted to the news of the MP’s death by telling members they would “just shed one skin for another”. The north-west contingent continued to meet in pubs and trained together at a mixed martial arts gym in Warrington, it was alleged.

Mullen, however, became disillusioned and began leaking information about National Action to the campaign group Hope Not Hate. By July 2017, Renshaw was on police bail for making hate speeches, for which he was later convicted.

Having decided to try to die via “suicide by cop” rather than face a seven-year jail term, he bought a large machete to take revenge on Henderson and kill Cooper. Renshaw unveiled his plan at the Friar Penketh pub in Warrington on 1 July 2017. Afterwards, Mullen, 25, from Widnes, Cheshire, reported the threat to Hope Not Hate and Renshaw was arrested.

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, Mullen added.

As she discharged the jury from returning verdicts, Mrs Justice McGowan told them: “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 17 May.