London, July 31 - A British soldier is facing court martial after refusing to return to Afghanistan, claiming the British mission there is doomed to failure.

Lance Corporal Joe Glenton, from the northern city of York, handed Prime Minister Gordon Brown a letter Thursday condemning the Afghan war and demanding the withdrawal of British troops.

Glenton, a 27-year-old from the Royal Logistic Corps, is thought to be the first British serving soldier to speak out publicly against the Afghan war.

'I don't believe our cause is just. I think it's adversely affecting the Afghan people as well as the British Army and their families,' Glenton wrote in the midst of a major debate in Britain over the Afghan war.

Glenton said he feared his fellow soldiers had become a tool of US foreign policy.

'I believe this unethical short-changing of such proud men and women has caused immeasurable suffering not only to families of British service personnel who have been killed and injured, but also to the noble people of Afghanistan,' he wrote.