Ocalan, 57, who launched a bloody Kurdish rebellion in southeast Turkey in 1984, was condemned to death in 1999 for treason, but his sentence was commuted to life imprisonment in 2002 after Turkey abolished capital punishment as part of efforts to align with European Union democracy norms.

He had a heart attack Tuesday in his prison on the Turkish island of Imrali, his Italian lawyers Giuliano Piasapia, Luigi Saraceni and Arturo Salerno said.

They appealed to the European Union and the European Committee for the Prevention of Torture to allow both them and his family to see Ocalan to check about his health.

Ocalan last month formally asked to be retried in Turkey after the European Court of Human Rights (ECHR) ruled last year that his trial was unfair.

Ocalan's demand poses a legal challenge to the government because current laws do not allow for his retrial, but Ankara is under pressure to comply with the rulings of the court, another of his lawyers, Ibrahim Bilmez, has said.

Recommending a retrial, the court ruled in May that the Turkish court that convicted Ocalan was not impartial because it included a military judge during part of the trial and because Ocalan and his lawyers were denied the required time and facilities to prepare their defense.

Ankara has said it will respect the ruling, but the authorities have so far failed to clarify how they will proceed.

Turkey and a number of Western countries including the European Union and the United States consider Ocalan's separatist Kurdistan Workers' Party (PKK) a terrorist organization.