A TURKISH court has sentenced a former military commander to life in prison and dozens of others including opposition MPs to long terms for plotting against the government, in a case that has exposed deep divisions in the country.

Retired military chief of staff General Ilker Basbug was sentenced to life yesterday for his role in the Ergenekon conspiracy to overthrow the government of Prime Minister Tayyip Erdogan.

Announcing verdicts on the nearly 300 defendants in the case, the judges also sentenced three serving parliamentarians from the opposition Republican People's Party (CHP) to between 12 and 35 years in prison.

Earlier, security forces fired tear gas in fields around the courthouse in the Silivri jail complex, west of Istanbul, as defendants' supporters gathered to protest against the five-year trial, a landmark case in the decade-long battle between Mr Erdogan and the secularist establishment.

Prosecutors say an alleged network of secular arch-nationalists, code-named Ergenekon, pursued extra-judicial killings and bombings in order to trigger a military coup, an example of the anti-democratic forces which Mr Erdogan says his Islamist-rooted AK Party has fought to stamp out.

Critics, including the main opposition party, have said the charges are trumped up, aimed at stifling opposition and taming the secularist establishment.