Lech Walesa led the Soviet bloc's first independent trade union, Solidarity
A libel trial has started in Poland over charges former President Lech Walesa once worked as a communist spy.
The court case pits the anti-communist leader against his one-time ally and successor as president, Lech Kaczynski.
The court case was adjourned until 18 December to allow more time for preparation.
Mr Walesa, now 66, is seeking a retraction of a claim made by Mr Kaczynski that he spied for the communist secret service in the 1970s.
He is also seeking 100,000 zloty (24,000 euros; £21,700) in damages.
Neither man was present in the Warsaw court for the start of Mr Walesa's lawsuit.
"As long as I have a court verdict favourable to me, nobody - not even the head of state - can publicly state that it's not true," Mr Walesa was quoted as telling a Polish television station ahead of the trial.
The former Solidarity leader has always denied he worked as a communist agent, and was cleared of earlier spying allegations by a special court in 2000.
Judges concluded that former SB security service agents had forged documents in his file in a bid to prevent him receiving the Nobel Peace prize in 1983.
Earlier this year he threatened to leave Poland after a second book accused him of being a communist spy as a young man.