Three UK bankers facing fraud charges connected to the collapse of Enron have appealed to the High Court in an effort to prevent their extradition to the US.
The three deny they have done anything wrong
They are seeking a ruling to compel the Serious Fraud Office (SFO) to say why it will not prosecute them in the UK.
In a test case of new legislation, the men contend they have a right to a trial in the country where the alleged offences were committed.
The men also do not believe they will get a fair trial in the US.
The charges relate to when the three bankers - David Bermingham, Gary Mulgrew and Giles Darby - worked for a unit of NatWest.
They have been accused of working in partnership with Enron's former chief financial officer Andrew Fastow and global financial chief Michael Kopper to defraud NatWest.
US authorities have brought seven indictments of wire fraud - illegally gaining money via international banking systems.
Each indictment carries a maximum term of five years, meaning a possible sentence in the US of 35 years.
The men are alleged to have made $7m after allegedly defrauding former employer Greenwich NatWest, the capital markets division of NatWest, by secretly investing in an "off-balance sheet" Enron partnership.
They admit making the money but deny their actions amounted to a criminal offence.
They said that when the Enron scandal first broke in 2001, and before any criminal investigation into the company, they went voluntarily to the Financial Services Authority (FSA) in the UK to inform them of their contacts with Enron officials.
But neither the FSA, the SFO nor NatWest chose to take any action.
US prosecutors want the men to face trial in Texas, home of energy giant Enron.
The extradition falls under UK legislation, which came into force in January 2004, and was designed to speed up the extradition of suspected terrorists.
In October, a judge ruled the trio could be extradited to the US.
The Home Secretary's formal decision on the ruling is due next month but the men are expected to appeal if the decision goes against them.
The men have now applied to the High Court for permission to launch a judicial review against the decision of the SFO not to investigate the claims against them.
"We have tried every which way we can over the last two years to get anybody and everybody to look at this from the perspective of investigating and if necessary - if they believe there is a case to answer - then a prosecution," Mr Bermingham told BBC News.
"There are huge ramifications for other people, particularly business people who may be accused by the US government."
He added: "If we are extradited over there, we are going to spend all our time prior to our trial in a US prison trying to defend a case when everything we need to defend it - witnesses, materials and evidence are over here."
Mr Bermingham also said he was worried about the pressure on people charged in federal cases in the US to enter into plea bargains.
"Unless we can establish some responsibility here on behalf of the prosecuting authorities to look at allegations that are specifically UK as to victims, perpetrators, conduct and so on, then we are liable to be extradited, effectively without evidence, into a jurisdiction where we have no ability to defend ourselves," he said.
The SFO told the BBC it would "be inappropriate to comment" on the reported developments.