Home Secretary Theresa May is due to announce whether computer hacker Gary McKinnon will be extradited to the US.Mr McKinnon, who admits accessing US government computers but claims he was looking for evidence of UFOs, has been fighting extradition since 2006.The 46-year-old, who has been diagnosed with Asperger’s Syndrome, could face 60 years in jail if convicted in the US.Meanwhile, reports suggest that Mrs May will also announce changes to Britain’s extradition arrangements with the US.Mr McKinnon’s case has been highlighted by critics who say it is too easy for the US to demand the handover of UK citizens. David Cameron raised the issue with President Barack Obama during a meeting at the White House in March and said he would like to see a review.Court decision The Daily Mail reports the home secretary is planning to introduce a measure that would make it more likely UK citizens would be tried in the UK - if that is where their alleged crimes took place.The newspaper says the introduction of the so-called forum bar means a court hearing would have to be held to decide where a person should stand trial.It says Mrs May will make the announcement when she addresses the Commons to give her ruling on Mr McKinnon, from Wood Green, north London.Mr McKinnon’s lawyer, Karen Todner, said she had been calling for such a move for years.She told the BBC: "It would be absolutely fantastic if she does bring that in - but she must combine it with not sending Gary.”BBC legal correspondent Clive Coleman said this would be "seismic” for the UK’s extradition arrangements with the US.He said the measure was already part of an amendment to the Extradition Act but had never been given legislative force - it would require the approval of both Houses of Parliament.Psychiatrist assessment US authorities have described the Glasgow-born hacker’s actions as the "biggest military computer hack of all time” and have demanded he face justice in America.They insisted his hacking was "intentional and calculated to influence and affect the US government by intimidation and coercion”.The Americans said his actions caused $800,000 (£487,000) worth of damage to military computer systems.