Mr McKinnon's lawyers argue he should be tried in the UK
Home Secretary Theresa May has agreed to an adjournment in the extradition case of computer hacker Gary McKinnon.
A judge was due to rule on whether her predecessor Alan Johnson was wrong to grant the request by the US.
Lawyers for Mr McKinnon, 44, from north London, made representations to the new government as part of a long campaign to prevent an American trial.
Mrs May "considered the proposal" and a Home Office application to delay the High Court decision is to be made.
Mr McKinnon's lawyer Karen Todner said: "The secretary of state, having recently taken office and having received further representations from the claimant's representatives, wishes to have appropriate time fully to consider the issues in the case."
She added: "We are hoping Theresa May will look at our representations and agree Gary should not be extradited."
Glasgow-born Mr McKinnon, who has Asperger's syndrome, is accused of hacking into sensitive US military computers causing £425,000 ($700,000) damage. He admits breaking into the system but says he was seeking evidence of UFOs.
His lawyers have argued he is unfit to be extradited and should be charged by the UK authorities.
Ms Todner said the home secretary would consider medical evidence supporting their case.
A judge at the High Court was set to give a ruling next week in a judicial review examining Mr Johnson's decision that a US trial would not breach Mr McKinnon's human rights.
Mr Johnson had said he had received a guarantee from the US government that Mr McKinnon would receive "appropriate medical care and treatment", including counselling and medication.
The adjournment comes as the Conservative-Liberal Democrat coalition promised a fresh look at extradition arrangements between the countries.
In its policy programme document, the parties say the government is to "review the operation" of the Extradition Act and the 2003 US/UK extradition treaty "to make sure it is even-handed".
Campaigners have expressed concerns that the treaty, agreed between Washington and London in the aftermath of the 9/11 attacks, was being used to seek extradition for offences which it was not originally intended to cover.
Mr McKinnon's mother Janis Sharp said that while in opposition both the Conservatives and Liberal Democrats had condemned the use of the extradition treaty in her son's case.
"I am therefore confident that the new government will do the right thing and halt Gary's extradition so that he may face trial in the UK, without the further unnecessary risks to his mental health that extradition would bring".