This is the latest development in the long-running case of McKinnon, 42, who faced extradition to the United States following the European Court of Human Rights’ decision in August 2008.
If McKinnon were found guilty and sentenced in the UK, it would lessen the chance of extradition. He and his supporters fear that US prosecution will treat him as a scapegoat and present him with up to 70 years in prison.
According to his lawyer, Karen Todner, the confession reflects "his culpability for what he did".
McKinnon maintains he hacked into the networks to search for evidence of anti-gravity propulsion systems and other advanced technology. However, he still denies causing damage, which the US authorities put at £532 500 ($800 000).
Also, US authorities allege that McKinnon stole 950 passwords and deleted files at a naval base in New Jersey, responsible for replenishing munitions and supplies for the Atlantic fleet.
“McKinnon has had tremendous support from the hacker community and even ordinary people – many IT workers have a lot of sympathy for his ongoing plight and would rather see him tried in Britain as opposed to the US,” said Graham Cluley, senior technology consultant at web security firm, Sophos.
However Cluley adds that “Any form of hacking is illegal and should be punished as such, and hacking into US government networks is bound to come with harsh repercussions – anyone thinking about engaging in these types of activities in the future should think twice”.