WARSAW — Threatening a general strike, throwing smoke grenades and blowing whistles, around 100,000 Polish union members marched through Warsaw on Saturday to vent their anger against the government's labor and wage policies. Prime Minister Donald Tusk's government is rapidly losing popularity after recently raising the retirement age, announcing a reform of the pension system and relaxing some labor code provisions that allow for longer daily and weekly working hours. The demonstrators marched to the historic Castle Square with flags and balloons in national white-and-red colors and with banners saying “Tusk's government Must Go,” and with individual plaques reading: “I am Tusk's Slave.” They converged on Warsaw from all over Poland on the last of four days of major protests in the city that also included meetings with politicians and debates with labor market experts. Some of them have camped in front of parliament since their first march Wednesday. The organizers — Poland's largest union, OPZZ, Solidarity and groups representing various professions — said about 120,000 participated in the march Saturday. City authorities said there were some 100,000. The unionists said that the policies of Tusk's pro-market government hurt the interests of workers and of their families. Tusk is in his sixth year in office and is Poland's longest-serving premier since the fall of communism in 1989. A nurse interviewed on TVN24 said that after 31 years in her job her monthly earnings are 2,000 zlotys ($630). — AP