CAMPAIGNERS for an Asperger's sufferer wanted in the US on hacking charges have stepped up efforts to keep him in the UK ahead of President Barack Obama's first state visit later this month.

An extradition order is hanging over Palmers Green resident Gary McKinnon, who is accused of hacking into sensitive US government databases and allegedly causing hundreds of thousands of dollars worth of damage.

His mother, Janis Sharp, last week wrote an open letter to President Obama, pleading for him to call off the extradition process and allow Mr McKinnon to be tried in the UK.

She argues he has suffered years of mental torment because of his crimes, committed in 2002, and would be driven to suicide if he was extradited to the United States.

However, her plea appears to have fallen on deaf ears after US Attorney General Eric Holder, speaking to ITV, reaffirmed the Obama administration's determination to pursue the 45-year-old.

He said: “We will contiunue to take all the necessary steps to have him extradited to the United States and held accountable for the crimes that he committed.

“We have a good extradition relationship with the UK and I am confident that the review that the Home Secretary will make will be an appropriate one.”

Home Secretary Theresa May is currently assessing the case, to decide whether to overrule court decisions allowing extradition.

But Mr Holder said: “McKinnon is a person who committed serious crimes which resulted in about a million dollars of damage in the United States.

“There has been a review by seven judges in the UK who made the determination extradition was appropriate, and the previous Home Secretary made the determination that extradition was appropriate.”

Mr McKinnon has always claimed he hacked into the US systems to look for signs of UFOs, rather than to pose a threat to national security.

President Obama is due to fly in to the UK on Tuesday, May 24, for a three-day visit.