Selahattin Demirtas, leader of the Peace and Democracy Party, said he's received Ocalan's "road map" for peace talks with the Turkish government.
Turkish leaders recently reached out to Ocalan to find a solution to a crisis brewing since the 1980s. The peace process comes after the killing of three high-ranking members of the separatist movement in early January in Paris.
Demirtas didn't outline the provisions in Ocalan's letter, though Turkish newspaper Today's Zaman reports a cease-fire and repatriation are part of the deal.
The Turkish newspaper puts the death toll from the 29-year conflict between the Kurdistan Workers' Party, known by its Turkish initials PKK, and the military at 40,000.
The pro-Kurdish leader says his party was considering sending a delegation to meet the jailed leader to discuss further prospects for peace. He warned the ruling Justice and Development Party, meanwhile, to avoid using the PKK negotiations for political gain.
Turkish Deputy Prime Minister Bekir Bozdag said last week there's no chance Ocalan would be released.