Twenty diplomats attended a military court on Monday to hear an appeal to extend the sentence of non-violent protest leader Abdallah Abu Rahmah, the Popular Struggle Coordination Committee said.

Abu Rahmah was due to be released on 18 November, having served a 12-month sentence. The anti-wall activist was convicted of incitement and organizing illegal demonstrations for his role in Bil'in's campaign against the construction of Israel's wall on its lands.

He has been kept in detention at the military prosecution's request despite having served the term of his sentence.

The prosecution is demanding a sentence of at least two years, PSCC spokesman Jonathan Pollak said.

A military judge heard the prosecution's appeal but did not set a date to announce his decision.

According to his supporters, Abu Rahmah's conviction was based only on testimonies of minors who were arrested in the middle of the night and denied legal counsel despite significant ills in their questioning. His detention drew harsh criticism from the EU, the Spanish parliament and human rights organizations.

The British consul general and the Maltese head of mission were among many high-profile officials in the courtroom, Pollack said.

The Elders, a group of international public figures brought together by Nelson Mandela, issued a statement Monday calling for Abu Rahmah's immediate release. Members of the group met Abu Rahmah on a visit to Bil'in in 2009.

"Desmond Tutu, Ela Bhatt, Gro Brundtland, Fernando Henrique Cardoso, Jimmy Carter and Mary Robinson were impressed by Abu Rahmah and praised his wise leadership of effective, non-violent civil action," the statement said.

Former US President Jimmy Carter added that "Israeli military prosecutors want to extend Abdallah Abu Rahmah's sentence as a deterrent to others who may follow his example. The Elders believe that his example of non-violent resistance against the occupation is a model that others should follow."

Abu Rahmah is the recipient of the the Carl Von Ossietzky Medal for Outstanding Service in the Realization of Basic Human Rights, which awarded by the International League for Human Rights in Berlin.