London - A British court begins hearings on Monday to decide whether Julian Assange should be extradited to the United States almost a decade after his WikiLeaks website enraged Washington by leaking secret US documents.

A hero to admirers who say he has exposed abuses of power, Assange is cast by critics as a dangerous enemy of the state who has undermined Western security. He says the extradition is politically motivated by those embarrassed by his revelations.

The 48-year-old is wanted by the United States on 18 criminal counts of conspiring to hack government computers and violating an espionage law and could spend decades in prison if convicted.

Now, some 10 months after he was dragged from the Ecuadorean embassy where he had been holed up for seven years, Judge Vanessa Baraitser will hear arguments as to why he should or should not be sent to the United States.

Jennifer Robinson, Assange's lawyer, says his case could lead to criminalising activities crucial to investigative journalists and his work has shed an unprecedented light on how the United States conducted its wars in Iraq and Afghanistan.