Jacek Kuron, 70, who led the struggle against Poland's communist leaders as a dissident in the 1970s and later became a popular government minister, died June 17 at the Warsaw Interior Ministry hospital. No cause of death was reported.

Mr. Kuron was believed to have played an important role in the founding of Lech Walesa's Solidarity movement, which went on to play a central role in post-communist Polish governments. Walesa said Mr. Kuron "was the unquestionable leader of anti-communist struggle in the 1970s and '80s."

Vaclav Havel, who led the peaceful Velvet Revolution that brought down communism in Czechoslovakia, said Mr. Kuron was an inspiration to dissidents in his country.

Born in the eastern Polish city of Lvov, now in Ukraine, Mr. Kuron became a strong supporter of the communist regime imposed by the Soviet Union following World War II.

He had become disenchanted by 1964 and wrote a letter to the party accusing its members of betraying communist ideals and infringing on people's freedoms. The party expelled Mr. Kuron and jailed him for more than three years. Many other incarcerations followed between 1966 and 1984 as Mr. Kuron took on a leading role in organizing student and worker demonstrations and other pro-democracy agitation.

Although Walesa was the popular leader of the Solidarity movement, Mr. Kuron was widely seen as the intellectual force behind its founding in 1980.

He was jailed Dec. 13, 1981, in a nationwide nighttime sweep that netted hundreds of Solidarity leaders after the country's communist leader, Gen. Wojciech Jaruzelski, imposed martial law.

Mr. Kuron played a major role in the 1989 round-table talks between Solidarity and the communist authorities, which led to Poland's first free elections and the ouster of communists.

He went on to became labor minister in the first democratic government, between 1989 and 1990 under Solidarity Prime Minister Tadeusz Mazowiecki, gaining wide popularity in his fight to help the country's poor. He introduced welfare programs for the unemployed and opened outdoor soup kitchens -- starting the program by himself taking to the streets to serve the food.

In a nod to his efforts, welfare payments became known as "Kuron's money" and the food "Kuron's soup."

Mr. Kuron, who was almost always clad in jeans and a denim jacket, served again as labor minister under Solidarity's third government, under Prime Minister Hanna Suchocka, between 1992 and 1993.

Mr. Kuron made an unsuccessful bid for president in 1995, after which his health deteriorated significantly and he retreated from public life.

The Times of London reported that his first wife, Grazyna, died while he was interned under martial law. Survivors include his second wife, Danuta, and a son from his first marriage.

Jacek Kuron was named labor minister in Poland's first democratic government.