Labor Minister Wladyslaw Kosiniak-Kamysz has accused the union members of breaking off talks, Polskie Radio reported Friday.
"You can argue, discuss, but first of all you have to sit down at the table," he said.
Kosiniak-Kamysz claimed one of the unions' major demands -- for a faster increase in the minimum wage -- had been met because the minimum wage will rise to $531 a month, 45 percent of the national average, by 2014.
The initial protests opposed proposals to allow temporary labor contracts under which employers can withhold overtime pay for a year, The New York Times reported.
Protesters are calling for a repeal of an increase in the retirement age to 67.
The government's bargaining position was weakened Thursday when Jacek Zalek, a member of Poland's lower house of parliament, resigned from the ruling Civic Platform party, leaving the government with 232 votes in the 460-seat chamber.
Explaining his resignation at a news conference Wednesday, Zalek said, "Those protests are a sign that we were unable to rise to the challenges that were put before us by Poles."
The first day of the protests, Wednesday, drew about 23,000 people. Organizers predict 60,000 will show up Saturday, the final day set for the demonstrations.