A British man who has been on hunger strike in a US prison since September 2007 can legally be force-fed by prison authorities, a court has ruled.

William Coleman, who is serving an eight-year sentence for raping his wife, is protesting at what he says is a corrupt judicial system. The case has reignited a debate over whether force-feeding prisoners contravenes their human rights.

Coleman, from Liverpool, argued that the force-feedings undermine his rights to free speech and to refuse medical treatment, as prison authorities claimed they must ensure prisoners' health and safety.

His weight has dropped from nearly 18 stone when he was first jailed to under 10 after he stopped accepting fluids.

The 48-year-old's lawyers have compared his hunger strike to that of the suffragettes of the early 20th century and to Gandhi's protests.

But Superior Court Judge James Graham, who presided over the case, said: "Neither the state nor federal free-speech guarantees allow Coleman to continue his hunger strike in contradiction to the penological needs of the prison."

The American Civil Liberties Union (ACLU) of Connecticut condemned the ruling as "flawed at its core because it disregards the choice of a competent individual to refuse medical treatment".

David McGuire, an ACLU lawyer who is representing Coleman, said: "Mr Coleman's hunger strike is symbolic political speech and is entitled to protection under the United States and Connecticut constitutions."

Coleman, a former women's university football coach who is due for release in 2012, is being held in the Corrigan-Radgowski Correctional Center in Connecticut. He maintains his innocence, arguing that his ex-wife falsely accused him of rape in order to gain custody of their two young sons.

A doctor who gave evidence to the court, Dr Suzanne Ducate, said Coleman was not trying to commit suicide, but merely to protest. "He's told me he doesn't want to die but he's willing to die," she said. "I don't personally know how to define that in terms of suicide." She said that Coleman's hunger strike had encouraged copy-cat protests at the prison.

He was force-fed a dozen times after his weight dropped from 250lbs to 139lbs in September 2008 when he began to refuse fluids. Coleman complained that force-feedings were extremely painful, causing him to vomit and bleed. "The force-feedings were very painful," his lawyer said.

The case has generated much debate. The respected medical journal The Lancet has criticised the force-feeding of prisoners, pointing out that the practice is forbidden by the World Medical Association.