In a letter to a constituent seen by The Daily Telegraph, the business secretary reveals that Liberal Democrat members of the Government are working to overturn the legislation so that it is less “lopsided”.
The move could create a clash with the Attorney General, Dominic Grieve, who has said that problems with the treaty are “not readily curable”.
The treaty, which has been controversially used against a number of businessmen in the UK including the NatWest Three, allows American authorities to extradite British citizens with less evidence than would be needed for the UK to extradite a US citizen.
Last month the treaty was back in the headlines after Christopher Tappin, a retired businessman from Orpington, Kent, was extradited to the US to face allegations of selling specialised batteries for military use to Iran. He denies the claims and is now being held in custody in a high-security prison in New Mexico.
“The treaty is wrong in principle,” Mr Cable said in the letter dated February 24. “Extradition is based on the principle of reciprocity. For a state to give up one of its citizens to another jurisdiction can be justified only by the confident knowledge that citizens of both states have equal rights.
“I can assure you that I shall be working with my Liberal Democrat colleagues, legal experts and campaigners to identify measures that would end the ‘lopsided’ nature of our extradition arrangements with America.”
Mr Cable’s comments come as The Daily Telegraph publishes an exclusive extract of the new book by David Bermingham, one of the NatWest Three.
In the book, A Price to Pay, Mr Bermingham reveals how he was extradited to America to face charges of fraud and sparked a major campaign in the UK against the extradition treaty.
Mr Bermingham, along with Giles Darby and Gary Mulgrew, was accused of making an illegal $7.3m (£4.6m) profit from a deal with Enron, the energy giant that collapsed amid allegations of fraud in 2001.
It was alleged that three Britons had defrauded NatWest, their former employer, of the money. All three pleaded guilty in the US and were sentenced to 37-months in prison.
Mr Bermingham said that he pleaded guilty so that he can return home to the UK more quickly. All three men have denied they did anything wrong.
“The iniquities of the Extradition Act continue to be visited upon the citizens of the UK at an alarming rate,” Mr Bermingham says in the book. “Ian Norris, Gary McKinnon, Christopher Tappin and Richard O’Dwyer to name but a few. I want it to be over. But it isn’t.
“Being a profound cynic now in all matters political, I will believe that the Government intends to change the extradition legislation, as both the Conservatives and the Liberal Democrats vowed to do when in opposition, only when the amendments become law. Until then, the fight goes on.”