By Adam Easton
BBC correspondent in Warsaw
Jacek Kuron, one of Poland's most loved democracy activists and former adviser to the Solidarity movement leader, Lech Walesa, has died at the age of 70.
Kuron was one of Poland's most trusted politicians
Mr Kuron had spent four weeks in intensive care in a Warsaw hospital after suffering from a long illness.
Jailed three time by Poland's Communist authorities, Mr Kuron helped set up the "round table" talks between Solidarity activists and the party leaders.
The talks led to the country's first free elections in 1989.
For many years Jacek Kuron was the most trusted politician in Poland.
As the labour minister in the newly formed post-Communist government in the early 1990s, he introduced welfare programmes for the unemployed.
People still call unemployment 'Kuroniowka', as Poland was going through the difficult transformation from Communism to capitalism, known as shock therapy.
He personally served food in outdoor soup kitchens.
As other Solidarity activists got used to wearing smart suits in their new jobs, he never abandoned his trademark denim jacket, no matter how formal the situation.
The heavy-smoking historian had been an admirer of the Communist system after World War Two.
But he became disenchanted with it when he saw how it restricted social freedoms.
In 1980 he became an adviser to Lech Walesa, leader of the then fledgling Solidarity trade union movement.
Nine year later he took a leading role in the negotiations which led to the collapse of Communism without a single shot being fired.
Upon hearing of his death Mr Walesa said: "Without Jacek it would have been impossible."