The five, all aged around 20, had already been convicted on December 16 of insubordination after a court martial in Jaffa, near Tel Aviv, rejected their refusal to serve on grounds of conscience, saying their motives were political.

Matan Kaminer, Noam Bahat, Shimri Tsameret, Adam Maor and Hagai Matar have already served 13 months on remand but they will now have to serve a further 12 months behind bars.

"We did not expect anything else from the tribunal of an army which occupies and oppresses a whole people and from a regime which has forgotten the meaning of democracy," Matar told AFP.

Captain Yaron Kosteliz, assistant chief military prosecutor, described the ruling as "very important" because it made clear the limits of acceptable protest in a democracy.

"The judges held that the use of military service as a way of influencing public opinion was wrong," Kosteliz said. "In a democracy you have to use legitimate tools and not act in a way that is prohibited."

Kosteliz said their refusal was not "conscientious objection" but rather "selective objection" on political grounds.

"We have no problem with someone refusing on grounds of being a pacifist, but selective objection is not about refusing to serve in any army -- it's about refusing to serve in the Israeli army because of its activities in Judea and Samaria," he said, using the Biblical term for the West Bank.

The ruling was likely to deter anyone contemplating a refusal to serve, he said.

The group has been given until Wednesday to report to a military prison in northern Israel where they will serve their sentence.

Matar earlier accused the Israeli army of being "an instrument of violence which violates human rights and international conventions" in a letter to Defence Minister Shaul Mofaz.

All Israeli men aged over 18 have to serve three years national service.

WAR.WIRE