A Royal Navy medic was sentenced to seven months' detention in a military correction facility today after he was found guilty of disobeying a legal order by refusing to attend rifle training because of his "moral objection" to bearing arms and the war in Afghanistan.
Leading medical assistant Michael Lyons denied the offence at the court martial trial at Portsmouth Naval Base.
He was also demoted to the rank of able seaman and dismissed from the service.
His supporters stood up and applauded as he was marched from the court.
The court martial heard that Lyons, 25, from Plymouth, Devon, had been issued with his order to deploy to Camp Bastion, Afghanistan, in May last year.
He then applied through his superior officer to be considered as a conscientious objector in August.
But this was refused a week before he was due to attend the SA80 service rifle training at HMS Excellent in Portsmouth, Hampshire, on September 20.
On that day, he reported to Warrant Officer Robert Bainbridge and stated that he could not start the course because he had a "moral objection to bearing arms" and asked to be "re-rolled for non-combative duties", leading him to be charged with disobeying a lawful order.
He then entered his appeal over his conscientious objector status to the Advisory Committee on Conscientious Objectors (ACCO), which was rejected on December 17.
Fiona Edington, defending, said medics had a "protected status" under the Geneva convention, meaning that they were non-combatants who had a right to bear arms for self-defence and the protection of a patient.
She added that Lyons had developed a moral objection to the war in Afghanistan since he originally joined the navy at the age of 18.
She said: "Throughout the time he has behaved with impeccable politeness.
"This is an isolated incident by a man with a conscience."
Commander Darren Reed, prosecuting, said: "What distinguishes a military force from an armed mob is discipline."
Last December, Lyons became the first person to appear before ACCO for 14 years.
The committee rejected his claim, saying he was a "political objector" not a "conscientious objector".
The court martial heard that Lyons was still awaiting formal notification from Defence Secretary Liam Fox.
Ms Edington said: "He (Lyons) remains, in his eyes, a conscientious objector."
A previous hearing was told that Lyons's case was only the third court martial to be held with conscientious objection as a defence.
The ACCO heard that Lyons decided he could not serve in Afghanistan after he read the WikiLeaks revelations about the conflict.
Lyons, who comes from a military family and is the great-grandson of a decorated Second World War hero, told the committee: "I was unable to find a real, just and noble cause to go out but I still had a sense of duty to my country.
"It was a big dilemma. Soon after, a large number of military documents were leaked by WikiLeaks.
"Examples included a convoy of marines tearing down a six-mile highway, firing at people with no discrimination.
"Being in the military, most people's view was you just have to go out there and do what you're told to do.
"I came to the conclusion I couldn't serve on a moral ground and I couldn't see any political reason for being there."
He said he was further put off when he learnt he might not be able to treat everyone, regardless of who they were.
He said: "It seems from previous testimony and courses I've done that even going out as a medic with all good intention, if you're at a patrol base or forward operating base, it's likely you'll have to use your weapon and will have to turn civilians away who are in need of medical aid."
He added: "If more people in my position stood up, there would be a lot less innocent lives lost around the world."
One of the previous court martial cases involving conscientious objection as a defence was Muslim reservist Mohisin Khan, from Ipswich, who refused to serve with the RAF as a medic.
He lost his appeal for going absent without leave (Awol) in 2004.
In the other case, Lance Corporal Joe Glenton, from York, lost his appeal last year against a nine-month jail sentence after he went Awol prior to his second deployment to Afghanistan.