Janis Sharp believes the new coalition will honour its promise
The mother of UK computer hacker Gary McKinnon says she is "confident" the new coalition will halt his extradition to the US as early as next week.
Janis Sharp said the Conservatives and Liberal Democrats promised before the election he would be tried in the UK.
They would not want to be the type of government which broke its promises as soon as it took power, she said.
Glasgow-born Mr McKinnon is accused of breaking into the US military computer system and faces 60 years in jail.
The 44-year-old, who has Asperger's syndrome, says he was on a "moral crusade" to find classified documents about UFOs.
Ms Sharp has spearheaded a public campaign to keep her son in the UK, and many opposition politicians at the time, including David Cameron and Nick Clegg, were critical of Labour for allowing the extradition.
It (the coalition) has said goodbye to the old thing of saying one thing and doing another and I totally trust they will do as they have said
She said she had "total trust" that the new coalition would "honour its promise".
"We are expecting, probably next week, for them to end Gary's nightmare and halt the extradition process permanently and allow Gary to be tried here as promised," she said.
"This government is new, it's fresh and they don't want to be seen as the kind of government that is going to break its promises as soon as it gets in."
Alex Bushill, BBC News
Janis Sharp knows about detail. She can quote legal precedent and judicial rulings. The reason is simple: She is fighting to keep her son Gary McKinnon in Britain.
She says the process of being extradited to the US is punishment enough for Gary, who has Asperger's syndrome.
She tells how he worries about catching a bus, hates to leave home and wouldn't dream of travelling abroad. But now he faces being sent across the Atlantic to stand trial for allegedly hacking into the Pentagon's computer systems.
Ms Sharp believes the extradition treaty she's been fighting for five years is unfair. She quotes the public endorsements she's had from Nick Clegg and David Cameron calling for her son's ordeal to end. But that was when they were in opposition.
Does she worry they won't keep their promises now they are in government? "I'm sure they will", she says, "how could this new politics mean more of the same old lies?"
They would not want to "wreck their reputation" so early on, she added.
"It has said goodbye to the old thing of saying one thing and doing another and I totally trust they will do as they have said," she said.
His legal team has already made "representations" to the new Home Secretary Theresa May to overrule the decision to allow his extradition.
At the end of this month, a judge is due to rule on whether the previous home secretary Alan Johnson was wrong to allow the extradition.
But Ms Sharp said her son's lawyers had applied for this judicial review to be cancelled because they were so "confident" his extradition would be stopped.
Meanwhile, the Foreign Secretary William Hague has promised the government will take a fresh look at extradition arrangements between the UK and the US.
The computer systems Mr McKinnon - now of Wood Green, north London - is accused of breaking into include those at the Pentagon.
The American authorities say his actions in 2001 and 2002 caused $800,000 (£487,000) damage but this is something he disputes.
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