"We call on the Lithuanian authorities to end the inhumane treatment of political prisoners, which calls into deep doubt that country's commitment to democracy," according to a statement to the Baltic News Service.
It was signed by 14 members of Parliament who are part of a Assembly seminar called "Europe's United Left," including four members from Russia, three from the Ukraine and one from Belarus, Czech Republic, Germany, Moldova, Portugal, Cyprus and Sweden.
The members also accused human rights organizations, the Council of Baltic Sea States and the Organization for Security and Cooperation in Europe of ignoring the "worst violations of human rights in the Republic of Lithuania," and called on them to exert pressure on Lithuanian authorities.
Statement authors said the six organizers of the January 1991 Soviet attempt to overthrow the Lithuanian government had been convicted "on an inadequate legal basis" and called the imprisonment of elderly and sick convicts their "slow and conscientious murder."
The Lithuanian Appellate Court last week adjourned the appeal hearings of the convicted six until August 21.
The Vilnius District Court convicted the men last August.