Radical Muslim cleric Abu Hamza faces extradition to the US on terrorism charges which could lead to the death penalty but British laws will prevent American prosecutors from seeking the ultimate punishment if the preacher is convicted.
The extradition request for Abu Hamza has been made under a new treaty between Britain and the US, signed in Washington 11 months ago, and implemented under UK law at the start of 2004.
Abu Hamza is also wanted by the authorities in Yemen
Article 7 of the treaty covers the death penalty and states that "the executive authority may refuse extradition unless the requesting state provides an assurance that the death penalty will not be imposed or, if imposed, will not be carried out."
This chimes with current practice governing extraditions between member states of the European Union and the US.
Moreover, a judgment of the European Court of Human Rights has upheld an absolute bar on extraditing someone who may face the death penalty in the requesting state.
So, on the face of it, the US Attorney-General John Ashcroft was addressing a domestic audience when he chose to refer to the death penalty in relation to the Abu Hamza case.
In practice, it seems inconceivable that the request will be granted if the possibility remains that the cleric could face execution.
However, there exist other concerns.
The new streamlined extradition procedure means that the US no longer has to back up each charge with detailed evidence.
It merely has to provide a summary of the charges and satisfy a district judge that they are in order.
The organisation Statewatch says the failed attempt by the US to extradite the Algerian pilot Lotfi Raissi on charges related to the 9/11 attacks, " raises doubts about the wisdom of removing the evidence requirement in the new treaty".
Even if the extradition does not go through, it is possible that Abu Hamza could be charged under UK law
Critics also point out that safeguards, which may block an extradition where the alleged offence has been committed on political grounds, have been diluted under the new law.
However, the extradition lawyer Louise Delahunt, says a court may still allow a challenge if there are grounds for believing that the Human Rights Act has been breached.
In this eventuality, the case could end up at the European Court in Strasbourg.
Even if the extradition does not go through, it is possible that Abu Hamza could be charged under UK law.
Some of the charges laid by the US involve conspiracy to take hostages and hostage-taking.
These have what is known as universal jurisdiction and are punishable in the British courts even though the alleged offences were committed abroad.