THE UNITED STATES has an independent legal system based on our own, which holds due process in high esteem. So why does just about everyone that the Americans want to extradite from the UK fight it tooth and nail?

One clue lies in a highly unusual protest taking place this afternoon in Central London. A silent, low-key demonstration will wend its way through the streets. There will be no banners, dress is strictly business attire and supporters include Sir Digby Jones of the CBI and Shami Chakrabarti of Liberty, not a pairing very often seen protesting together.

The march is being organised by business leaders angry at what they see as the UK’s unbalanced extradition treaty with the US. It comes two days after the European Court of Human Rights turned down a final plea by former NatWest bankers, the so-called NatWest Three, for an order blocking their extradition to the US on fraud charges relating to the demise of Enron, the energy group.

Why, then, is the business community so angry? The 2003 Extradition Act was introduced by the Government in the aftermath of 9/11. Prompted by the War on Terror, it followed the negotiation of an extradition treaty between the two nations.

Traditionally, countries wanting to extradite people from the UK had to produce prima facie evidence of the crime they were alleged to have committed. This was usually in the form of witness statements, and the production of evidence was regarded as an important protection. Under the 2003 Act, the Americans don’t have to do this. They need to outline only the alleged offence and the punishment,and provide an accurate description of the suspect. That’s whether the suspect is wanted for terrorism, white-collar crime or something else entirely. Yet we in Britain still have to produce prima facie evidence if we wish to extradite someone from the US.

And there’s another oddity. The American Senate still has not ratified the 2003 Treaty. This is often laid at the door of the Irish republican lobby and what is known as the “political offence exemption”. If the treaty is ratified it will take away from American courts the power they currently enjoy to resist extradition for crimes that are politically motivated. American courts since the time of Thomas Jefferson have never liked the idea of extraditing people for politically motivated crimes. It is now highly unfashionable in Europe, because these days it really only applies to suspected terrorists. So, in a tale of two terrorists, one here, one there, the Americans can extradite without producing evidence and unhindered by any kind of “politically motivated” exemption. The UK can’t. It faces a far higher evidential test, and if the US courts deem the crime to be politically motivated, they can stop extradition altogether.

Many lawyers here believe that there is a deep irony that the US Senate is refusing to ratify a treaty, provoked by the War on Terror and lopsided in America’s favour, because it is concerned about extraditing people to this country for terrorist offences.

Lawyers are also troubled by what happens when the extradited person stands trial in America. One rather astonishing example illustrates the point. If you are charged with five counts in the US and acquitted of four of them by the jury, the judge in sentencing is able and advised to take into account those four if he comes to the conclusion that you were guilty of the offences on a balance of probabilities. The implications of this are considerable. The federal sentencing guidelines that give the judge this power are advisory not compulsory, but judges are under pressure to follow them. Prosecutors are invited to report judges who fall below the standards set out in the guidelines.

There is also the question of the reach of the American justice system.If a complex international fraud is committed in various cities around the world, the Americans can try the case in the US if so much as one e-mail has passed through American territory. And if the crime has been committed abroad, judges are advised to see that as an aggravating feature in sentencing. American sentences are now far tougher than in Europe. With heavy discounts for guilty pleas, lawyers here fear that those extradited come under enormous pressure to plead guilty. If they fight the case and lose, they face far more severe sentences than they would here. The NatWest Three could face between 15 to 17 years if found guilty. Here it would be more like 18 months.

The Home Office disagrees that the system is unbalanced. It told the BBC this week that the 2003 Treaty ensures that the legitimate rights of requested persons are respected, and that the US is a trusted extradition partner with a mature legal system, and it guarantees appropriate safeguards within its domestic courts.

Whether the current extradition regime between the two countries is sustainable in the long run is debatable, but the coming together of business leaders and civil liberties groups in today’s protest will, however sedately, add to the pressure to look again at the extradition arrangements between ourselves and our special friend.

Clive Coleman is a barrister and the presenter of Law in Action on Radio 4

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