Around 100,000 angry Polish trade unionists marched through Warsaw Saturday in the finale of a four-day protest against the unpopular and increasingly fragile centre-right government.
The protest reflects widespread public gloom over a sharp economic slowdown in Poland, which has sent the coalition's popularity plunging to its lowest level since Prime Minister Donald Tusk took office in 2007.
"We're becoming slaves in our own country!", Marek Duda, leader of Poland's iconic right-of-centre Solidarity trade union said as public sector workers rallied for Tusk to step down.
Solidarity spokesman Marek Lewandowski told AFP: "We want the departure of Donald Tusk. This is the only way to change social policy in Poland."
In a rare show of agreement, left-wing unions also protesting Saturday echoed Solidarity.
"We can no longer tolerate policies leading to misery and poverty," OPZZ union head Jan Guz said, calling the protest a "final alarm bell" before a possible general strike.
Union members, including coal miners, railway, steel, health and shipyard workers -- the latter from Solidarity's cradle at the historic Gdansk shipyard -- descended on Warsaw from across the country.
Clad in hard hats and brandishing union flags they blared sirens, beat drums, blew whistles and halted traffic as they marched through the city centre.
Solidarity protesters followed a gilded statue of Tusk with one arm extended, mocking communist-era aesthetics. A funeral wreath laid at its foot read: "For Flexible Labour Policy".
"Wake Up Poland," read another banner in the largest protest Warsaw has seen in years.
Lewandowski said it drew 150,000 protestors from both right and left-wing unions. Warsaw city hall confirmed 100,000 were on the streets by 1200 GMT.
The unions have the support of a majority of Poles, according to an opinion poll by MillwardBrown on Tuesday: 59 percent of respondents said they backed demonstrations.
Anger is centered on recent changes in labour and pension policy.
"We want pensions at the age of 65 as before and not at the age of 67 as Tusk's reform would have it. We want better social policy and guarantees for employees," Lewandowski said.
Improved public sector wages, a higher minimum wage and job security -- particularly for young people -- are also on the union agenda.
"We want a government that will take care of our interests, so we can live in dignity," Solidarity protester Ryszard Czyska, told AFP.
After 30 years as a train driver, he takes home 2,500 zloty (595 euros, $792) per month, well under Poland's 4,900 zloty average wage.
Solidarity's cosy alliance with the populist right-wing opposition led by former prime minister Jaroslaw Kaczynski -- the twin of late president Lech -- gave Saturday's protest a political edge, particularly as Tusk's support in parliament is dwindling.
Three of Tusk's MPs have defected in recent weeks, cutting his majority to a fragile 232 seats in the 460-member lower house and raising the spectre of a minority government that could spell early elections ahead of 2015.
Recent opinion polls have shown Kaczynski's Law and Justice (PiS) party running well ahead of Tusk's Civic Platform (PO).
But Tusk argued Friday that his success in pushing through a revised 2013 budget -- widening the deficit by an extra 3.8 billion euros ($5 billion) -- proved that concern over the exodus of MPs are "unfounded".
Analysts said the vote suggested Tusk could still muster enough legislative clout to pass the 2014 budget and thus avoid snap elections that the PiS could win.
They also say the party would be unlikely to govern alone and has no ready ally willing to join forces with it.
A central European powerhouse of 38 million people, Poland is the only EU member to have maintained growth each year for two decades.
However the economy slowed to just 0.1 percent growth in the first quarter as Poland's main trade partners the eurozone struggled with recession.
Growth picked up to 0.4 percent in the second quarter, but by then a 5.6 billion euro revenue shortfall had emerged.
The economy is expected to grow by at least 1.5 percent this year, down from the original government estimate of 2.2 percent.