Johnson has informed the committee that he's examining medical reports on McKinnon's condition to determine if extraditing the hacker would constitute a breach of his human rights.

If it does, the extradition can be blocked, however, the Home Secretary has previously argued that beyond this his hands are tied by the controversial Extradition Act 2003 between the US and UK.

The treaty allows US authorities to demand a Briton's extradition without having to provide evidence. It also came under the Committee's scrutiny and was blasted for its "serious lack of equality", with Vaz recommending that the Home Secretary conduct a ""comprehensive review".

The Home Office swiftly rejected the call. "As the home secretary told the Home Affairs Select Committee, the evidence that must be provided for a US extradition request to proceed in the UK is in practice the same as for a UK request to proceed in the US.

The suggestion that the operation of the Extradition Act needs to be reviewed comprehensively is unnecessary. Unless the evidence shows that extradition would breach the European Convention on Human Rights it would be unlawful to refuse extradition," it stated.