By Alex Stevenson Follow @alex__stevenson
MPs seeking the urgent renegotiation of Britain's extradition treaty with the United States will make their case in parliament later.
The Commons will vote on the matter in backbench business time amid growing pressure about current arrangements.
Only 54 people have been extradited to Britain since 2004, compared to 123 people extradited the other way.
That may partly be because American authorities do not need to produce evidence to back up their extradition request, whereas their British counterparts do.
Former judge Sir Scott Baker, who conducted an independent review of the current treaty, said it did not operate in an "unbalanced" manner.
But MPs, who are expected to be granted a free vote on the issue, could put intense pressure on the government to act by passing a motion calling for action.
America's ambassador to Britain Louis Susman told MPs on the Commons' foreign affairs committee that the US believed the treaty was completely reasonable.
"The constant use of skewed arguments and wilful distortion of the facts by some to advance their own agendas remains of great concern to the United States," he said.
"It would be wrong to view the extradition treaty through the prism of individual cases where sentiment and emotion can cloud reality and lead to misrepresentation."
Much of the debate in Britain surrounding extradition focuses on the case of Gary McKinnon, who hacked into the Pentagon's computer systems ten years ago.
He has been diagnosed with Asperger's syndrome and the government has not yet decided whether he should be extradited.
His mother Janis Sharp, who won Liberty's 'close to home' gong at its human rights awards ceremony last month, said her son had been on bail longer than anyone else in this country.
"This government has said it's going to change the extradition treaty and I believe it will. They're going to introduce the right of evidence before the horrendous punishment of extradition can be carried out," she said.
"He hasn't murdered anyone, he hasn't raped anyone. he was in a computer in his bedroom. Of course what he did was wrong, he would not have been left alone for three-and-a-half years after the event.
"When this is changed, at least Gary will know that ten years of what is mental torture will have achieved something so that no one else will ever have to go through this again."