ANKARA, Dec 10 (Reuters) - Turkish journalist Mustafa Balbay took his oath of office as a member of parliament on Tuesday after his release from nearly five years in prison on security charges, raising hope among other jailed deputies that they could follow in his footsteps.
He was among 275 defendants including an ex-military chief, retired officers, academics, journalists and politicians jailed in August over an alleged plot to overthrow Prime Minister Tayyip Erdogan's Islamist-rooted government.
Balbay, sentenced to almost 35 years in prison, was freed pending appeal by an Istanbul court after the Constitutional Court ruled his pre-trial detention period of more than four years had violated his rights.
The ruling enabled him to take his oath a full 30 months after being elected for the main opposition Republican People's Party (CHP). Balbay denied any wrongdoing in the so-called "Ergenekon" conspiracy against the state.
"I swear upon my honour, before the great Turkish nation, to safeguard the existence and independence of the state," Balbay said at the parliamentary induction ceremony.
Balbay's wife and two children, seated in the spectators' gallery in the parliament, smiled and clapped as he read the oath. Many opposition MPs gave Balbay a standing ovation.
There are six other MPs jailed in Turkey - five from the pro-Kurdish Peace and Democracy Party (BDP), suspected of links to the militant Kurdish separatist PKK movement - and one a former soldier from the Nationalist Movement Party (MHP) who was jailed over an unrelated coup plot.
Balbay's release could set a precedent for the jailed BDP deputies, lawyers said. But the MHP deputy has already lost an appeal to the higher court, leaving him no chance of release under the ruling that freed Balbay.
AK deputies watched impassively as Balbay was sworn in but parliament speaker Cemil Cicek, also from the AK, welcomed him.
"I find it meaningful that your oath coincides with Human Rights Day. Whether a parliamentarian or an ordinary citizen, I wish that all those who are exposed to rights violations regain their rights and freedoms right away," he said.
The Constitutional Court ruled last week that the four years and nine months Balbay spent in prison pending trial had violated his rights to freedom and representation of the people as an elected parliamentarian. He was elected in 2011.
CHP lawmaker Mehmet Haberal, among the first to show up at the prison gates on Monday to welcome Balbay, was another Ergenekon defendant but was set free earlier because of the time he had served in prison pending trial.
However, if the Court of Appeals rejects Balbay's request for his conviction to be quashed, he may have to return to prison even though as a parliamentarian he would enjoy immunity from prosecution.
The next parliamentary election is due in 2015. (Writing by Ece Toksabay; Editing by Daren Butler and Mark Heinrich)