Tooting terror suspect Babar Ahmad begins his High Court appeal this Monday against an extradition treaty described as "illogical, inhumane and a total violation of human rights".

Mr Ahmad's father, Ashfaq, was joined by Mayor of London Ken Livingstone on Tuesday to denounce the 2003 extradition treaty which allows British citizens to be extradited to America, without evidence.

If sent to America, Mr Ahmad could be executed.

Mr Livingstone said: "I'm particularly concerned about the case of Babar Ahmad. It's a new position in British law. It allows the US to cherry-pick anyone it wants in Britain and not have to produce any substantial evidence."

The treaty allows British citizens to be extradited to the US without the need for prima facie evidence. Despite being introduced as part of the War on Terror, most of the 40 Britons currently fighting extradition are in fact white-collar workers involved in fraud cases. And the US Senate has not as yet ratified the treaty, meaning US citizens cannot be extradited to Britain without evidence.

Mr Livingstone added: "It's almost as if everyone in the world is becoming a second class citizen to the empire in the White House."

Ashfaq Ahmad said: "The controversial, one-sided 2003 extradition treaty is illogical, inhumane and a total violation of human rights. If Babar is extradited he will be subjected to torture and possibly the death sentence. It's therefore very important that this ill-conceived treaty be abolished as soon as possible."

Babar Ahmad, 31, has been in custody since August 2004 when he was arrested on a US extradition warrant. America accuses the computer expert of using websites to raise money for terrorist causes as well as urging Muslims to fight a holy war.

He had previously been arrested in December 2003 but the Metropolitan Police released him after six days without charge due to insufficient evidence.

His sister, Sara, 27, said: "We've been working hard and campaigning hard and we'll give it our best shot. We're up for the challenge. We've been bashed around by the authorities quite badly but we are willing to fight to the bitter end."

Tooting MP Sadiq Khan said: "Babar Ahmad's predicament has caught the imagination of hundreds if not thousands of people in Tooting. He was no different to me and many others in Tooting and that is the concern of many people."

awestbrook@london.newsquest.co.uk