Unlike the Communist Party in other post-Communist states like Poland and Hungary, which transformed themselves after 1989 into more mainstream center-left parties, the Czech Communist Party has studiously avoided a comprehensive overhaul.

Indeed, it is still flourishing and gained nearly 13 percent of the vote in the last parliamentary elections in 2006. Its supporters are mostly those who are fed up with politics as usual and regime nostalgics, many of them elderly pensioners, for whom life before 1989 seems better than today.

The Communist Party of Bohemia and Moravia, named after the two main regions of the Czech Republic, is the direct successor of the Czechoslovak Communist Party. While the party has sought to distance itself from its violent past, its many critics contend that it never really cut its umbilical cord to its pre-1989 predecessor — a contention the party vehemently denies.

Vojtech Filip, the Communist Party’s leader, was adamant in an interview that the party did not support undemocratic regime change. But he fell short of condemning the Marxist principle of revolution and called Karl Marx “the greatest thinker of the millennium.”

“We are a legal party and always act according to the Constitution,” he said.

Defending his party’s philosophy, Mr. Filip paradoxically invoked Vaclav Havel, the former Czech president who led the revolution that overthrew communism, arguing that Mr. Havel himself had equated contemporary Czech politics with “mafia-capitalism.”

Mr. Havel, who languished in prison during the Communist regime, has also called the Communist Party “a boulder weighing down” the political system. But many Czechs blame him for refusing to ban the party when he became president or to put on trial a system that allowed neighbors to send each other to labor camps. Some saw in his approach a noble effort to avoid polarizing the nation; others consider it a moral lapse that prevented the country from coming to terms with its past.

Lubos Dobrovsky, a former dissident and defense minister, who ran Mr. Havel’s office when he was president, argued that it was not possible to ban the Communist Party in the immediate aftermath of 1989 because the reform wing of the party had been an essential ally during the transition to democracy and helped avoid violence.