TEHRAN (AFP/Reuters) - Iranian hardliners accused Opposition leaders of treason on Sunday as defeated presidential challenger Mir Hossein Mousavi said the authorities used medieval torture to force confessions from protesters on trial over the election unrest. Former president Mohammad Khatami also said Saturdays mass trial of 100 protesters and prominent reformists was against the Constitution, putting him at loggerheads with hardliners in an escalating feud between rival factions. The powerful hardline wing took aim at both Opposition leaders, accusing them of trying to lead a velvet revolution after the June re-election of President Ahmadinejad and lodging a judicial complaint against Mousavi. And another 10 people were brought before a revolutionary court on Sunday on charges relating to the massive street protests that erupted after Ahmadinejad was returned to power in what the Opposition said was a rigged vote. Evidence of Khatami and Mousavis treason unveiled, thundered the headline in the hardline Kayhan newspaper. A group of hardline MPs stepped up the pressure on the Opposition, filing a complaint against Mousavi to the judiciary, the Fars news agency said. Those who issued statements and directed recent riots should be accountable for the bloodshed and go on trial, said Mohammad Taghi Rahbar, a hardline member of parliaments judicial commission. But Mousavi remained defiant and said confessions at Saturdays trial were extracted by torture. They expect a court, which itself is fraudulent, to prove that there was no fraud committed in the election, said Mousavi, a former post-revolution premier who lost to Ahmadinejad. His comments came after some reformists, including a prominent Khatami aide, made a dramatic climbdown at the trial, saying Ahmadinejads victory was clean and that they had been pushed into demonstrating against the results. The Tehran court dismissed the Opposition attacks, saying that securing a confession is one way of proving a crime and no legal expert has ever cast doubt on that. The 100 face charges including rioting, vandalism, having ties with counter-revolutionary groups and plotting a velvet revolution. They face a maximum jail term of five years if convicted, unless they are charged with being a mohareb or enemy of God, which can carry the death penalty. Iranian authorities have tightened pressure on their opponents by staging what former president Mohammad Khatami derided as a show trial of 100 reformists accused of trying to instigate a velvet revolution. Khatami, several of whose close associates were in the dock on Saturday, said the trial violated Irans constitution. Such show trials will directly harm the system and further damage public trust, he said on his website (www.khatami.ir).