The hopes of McKinnon - who has Asperger's syndrome - were dashed late last week when the Home Secretary said that the extradition would probably go ahead within the next week or so, causing his solicitor, Karen Todner, to announce plans to appeal to the European court of human rights.
It now transpires that the Home Secretary - who had originally decided the government will not intervene in the case of McKinnon last week - is reconsidering his position.
He told the House of Commons yesterday that he is now considering a request from McKinnon's legal team to extend the seven-day period they have to apply for a judicial review until 17 December.
Infosecurity notes that, for the first time, the Home Secretary conceded there are legitimate concerns over McKinnon's mental health, but said this did not prevent the hacker from being extradited to the US to face the charges.
"I am currently considering a request from Mr McKinnon's lawyers for an extension of the seven-day time limit", he told the House.
"There are legitimate concerns over Mr McKinnon's health and the US authorities have provided assurances, which were before the High Court in July, that his needs will be met", he added.
In his House of Commons statement - which took many observers by surprise - the Home Secretary also defended his decision not to intervened in the McKinnon case.
"I'm the only person who can make this decision and I have to make it on the basis of the facts and all the facts - and it is a quasi-judicial decision", he told the House.
Infosecurity notes that Johnson's stance comes after a sequence of previous Home Secretaries also rejected calls to act on the hacker McKinnon's behalf - although David Blunkett has since joined the campaign to protect McKinnon, following the announcement that the hacker had been diagnosed with Asperger's syndrome.
In his prepared presentation to the House, Johnson said he accepted the vulnerability of McKinnon, "as I accept the vulnerability of many cases going through for extradition".
"It's a very heavy burden on any Home Secretary's shoulders, but nevertheless my job is to uphold the law", he said.