Turkish army General Ilker Basbugs outburst on the second day of his trial was the most dramatic demonstration yet of tensions that have simmered between the armed forces and the prime minister, Tayyip Erdogan, who has reined in their influence since winning power in 2002.

Basbug, who headed the military between 2008-2010, declared the trial a "comedy" and said he did not recognise the judges' authority over him. He demanded referral to the Supreme Court.

The general's patience snapped when the court was played a tapped telephone conversation between two other suspects accused of planning to engineer a coup through bombings and assassinations in what has become known as the "Ergenekon" case.

Basbug switched on his microphone and, to laughter from spectators, many of them supporters, told the judges to stop playing the tapes. They were, he said, irrelevant to the case. "Your honour, this is a serious court, but it has become tabloidised. This is a black stain in history," Basbug, wearing a dark suit, said to applause from supporters.

The judge threatened to clear spectators from the courtroom. "Clear it, sir, do clear it," Basbug interjected angrily. "Even playing these tapes here is a shame." With that, the grey-haired general turned and strode out of the courtroom.

The general returned to the courtroom later, after the judges called a recess, but refused to answer questions. The case is being heard at a court in the high-security Silivri prison complex, where Basbug has been held since early January. The hearing was later adjourned until Thursday.

Basbug is accused of being among the leaders of an alleged network, known as Ergenekon, behind plots to topple a government many in the military and elsewhere in the secularist establishment suspect of harbouring a secret Islamist agenda. Erdogan, whose AK party embraces nationalists and centre-right elements as well as religious conservatives, denies his party has such ambitions.

Ergenekon is suspected of planning bombings, assassinations and disinformation to stir panic and precipitate an army coup. Hundreds have been arrested in the investigation that critics accuse the government of using as part of a campaign to suppress any opposition.

Basbug shook his head in disbelief and disapproval during the judge's questions and answered none of them.

During a break, he spoke to journalists to counter what he regarded as a slur on the reputation of the military, which for generations had been regarded by many as a guarantor against militant leftism and against Islamism.

"Do you know how many lieutenant-generals are in jail under this case?" he asked. "Four. Four lieutenant-generals, one vice chief of staff and one former chief of staff are in jail. "That means the general staff headquarters are being called terrorist. Noone can call the Turkish Armed Forces terrorists!...Is there an explanation for this? Am I wrong? Can you explain this to me?"

The military staged three coups between 1960 and 1980 and pressed an Islamist-led government from power in 1997. Erdogan has drawn on strong popular support, part born of economic success, to cut back that influence.

The generals, or "Pashas", have enjoyed a privileged place in society, the founder of modern secular Turkey, Mustafa Kemal Ataturk, having emerged from the officer corps. Critics have argued they had occupied a place effectively above the law.

Strains between Pashas and government have been more than evident in recent years in discreetly coded statements by both sides, but Basbug's outburst on Tuesday gave for the first time public vent to the depth of feeling.
The case against Basbug features websites allegedly set up by the military to spread "black propaganda" against the government until 2008, including one titled "Islamic fundamentalism".

"The websites had exaggerated news headlines on the threat from fundamentalism in Turkey designed to provoke the people against the executive organ and create an atmosphere of chaos in the country," the indictment said.