A British businessman has told the BBC he wants to bring a private prosecution against two UK terrorism suspects.
Karl Watkin said he wanted to prosecute Babar Ahmad and Talha Ahsan, rather than them face extradition to the US.
Mr Ahmad has been detained without trial for a record eight years. The US accuse him and Mr Ahsan of running a major jihadist website.
The men are understood to have confirmed involvement in the UK website - but have not admitted offences.
Mr Ahmad and Mr Ahsan are accused of involvement in Azzam.com, a website and publishing business which between 1996 and 2002 was at the heart of the radicalisation of English-speaking Muslims.
Although the website was based and operated from London, it was technically hosted in the US.
Neither of the suspects has been charged with an offence in the UK relating to Azzam, despite the fact that the investigation by US authorities includes evidence seized by the Metropolitan Police. The CPS has refused to prosecute Mr Ahmad or Mr Ahsan and has rejected calls by the men's lawyer to review that decision.
Mr Watkin, who is based in Newcastle and has interests in China and Australia, told the BBC he instructed his lawyers to prosecute because the alleged crimes took place in the UK and the CPS has not already acted.
He is among campaigners who oppose the 2003 Extradition Act, which critics say is unfair to British citizens.
Mr Watkins said: "I don't know whether these men are totally innocent or as guilty as hell - that's for a court to determine with the benefit of all the evidence.
"But as Britons living and working here, having potentially committed serious crimes here, there is no question, they should be tried here.
"The public interest demands it. We do not need to outsource our criminal justice system to America.
"Between them they've spent 14 years in British jails yet have not been charged with breaking any British law - that's crazy.
"Justice delayed is justice denied. So I want to see Ahmad and Ahsan in the dock."
Mr Watkin's lawyers have filed papers at court seeking a judge's approval to summons both men to a trial which he would pay for.
The lawyers have also written to the Director of Public Prosecutions Keir Starmer QC, asking his permission for a private prosecution under terrorism laws.
Anyone can bring a private prosecution if they can prove that it is in the public interest to do so. The DPP has the power to intervene to take on the case or to stop it.
If the DPP or a judge were to halt the proposed proceedings, the decision could face legal challenge, potentially halting the extradition.
The Babar Ahmad case, and the lack of a prosecution in the UK, has proved so controversial that it triggered a Parliamentary debate.
The BBC later challenged a government ban on interviewing Mr Ahmad over the case. The High Court ruled that the case and the issues it raised was so exceptional it was in the public interest for Mr Ahmad to be filmed in prison.
Mr Ahmad and Mr Ahsan are waiting for a final decision from the European Court of Human Rights on whether they should be sent to the US.
Mr Watkin said: "I know I am not alone - 149,000 people have already petitioned Parliament, demanding a British trial of these two British men.
"If the tables were turned, the Americans undoubtedly would have tried their own citizens in America, many years ago. It is a disgrace that our prosecuting agencies have refused to do so. I smell politics, not justice, at play.
"I am acting where politicians, the Metropolitan Police and the CPS have failed."
Earlier this year the CPS confirmed to the BBC that it has only seen "a small number of documents gathered as evidence by the police in this country" and those had been insufficient for a prosecution.
Both the courts and Home Secretary have approved the extraditions.
Neither the Crown Prosecution Service nor Babar Ahmad's campaign have commented on Mr Watkin's attempted prosecution.