Among those invited to speak at the conference on August 30 are North Korean Kang Cheol-Hwan, author of "Aquariums of Pyongyang: 10 years in the North Korean Gulag"; Vincuk Viachorka, chairman of the Belarus Popular Front; Maung Maung, general secretary of Burma's Federation of Trade Unions; and Blanca Reyes, a Cuban dissident living in Spain.
"We want to express our solidarity with their ambitions. We also want them to learn how Solidarity conducted its peaceful revolution," said Radek Sikorski, executive director of the New Atlantic Intitiative non-governmental organisation which is organising the conference.
"That way, they might be able to avoid the errors that we committed and take their full responsibilities once they have ousted the current regimes," said Sikorski, a former deputy foreign minister of Poland.
Other dignitaries expected at the conference are US Under-Secretary of State for European Affairs, Daniel Fried, and Polish-born Zbigniew Brzezinski, who was security adviser to former US president Jimmy Carter.
On August 14, 25 years ago, sacked electrician and workers' rights activist Lech Walesa scaled the gate of the Lenin shipyard in Gdansk to lead a strike that was to change the face of his native Poland and Europe.
Seventeen days after the start of the strike, Walesa declared victory for the workers, and the birth of Solidarity, the first free trade union in the communist bloc.