A nationwide strike called by Brazil's trade unions disrupted public transport and triggered road blocks in parts of the country Friday, ahead of protests against far-right President Jair Bolsonaro's pension reform.

Hours before the opening match of the Copa America in Sao Paulo, some metro lines in the country's biggest city were paralyzed as professors and students also prepared to take to the streets over the government's planned education spending cuts.

It will be the latest mass demonstration against Bolsonaro since he took office in January, but the timing could not be worse for the embattled president as Brazil prepares to play Bolivia in South America's showcase football tournament.

Bolsonaro was expected to attend the opener at Morumbi stadium where police sharpshooters will be deployed as part of increased security for the competition.

One of Brazil's main trade unions estimated 45 million workers had taken part in the strike.

Some 63 cities had been affected by the stoppage, with more than 80 cities recording demonstrations, G1 news site said.

The number of protesters is expected to balloon in the afternoon with demonstrations planned in Brazil's major cities.

Protesters have already blocked some roads in several cities, including Rio de Janeiro and Sao Paulo, where G1 said police had used tear gas to disperse demonstrators and clear the streets.

Brazilians were divided over the partial strike.

"This current government wants to destroy everything that we built decades ago so that's why I'm in favor (of the strike) and I am fighting against social inequality," Vania Santos, 49, told AFP in Rio.

In Sao Paulo, Flavio Moreira opposed the stoppage, however, saying it "hurts the commercial part" of the city.

Pension savings cut 

Bolsonaro's proposed overhaul of Brazil's pension system -- which he has warned will bankrupt the country if his plan is not approved -- is seen as key to getting a series of economic reforms through Congress.

But the changes, including an increase in the retirement age and workers' contributions, have faced resistance from trade unions and in the lower house of Congress, where Bolsonaro's ultraconservative Social Liberal Party has only around 10 percent of the seats.

A pared-back draft of the reform presented to Congress on Thursday -- which reduces expected savings from 1.2 trillion reais ($300 billion) in 10 years to around 900 billion reais -- did little to appease union leaders, who vowed to go ahead with the shutdown.

Such savings are seen as vital to repairing Brazil's finances and economy, which were devastated by a 2015-2016 crisis.

Economy minister Paulo Guedes, who is spearheading the government's reform agenda, has threatened to resign if the bill is not passed or is watered down significantly.

It caps a tumultuous six months for Bolsonaro, who has seen his popularity nosedive as he struggles to push his signature reform through a hostile Congress and keep Latin America's biggest economy from sliding back into recession.

More than 13 million people are unemployed, the latest data shows, with a record number giving up looking for a job.

Fighting between military and far-right factions of Bolsonaro's government has fueled chaos in his administration where his sons and right-wing writer and polemicist Olavo de Carvalho wield enormous influence.

Bolsonaro sacked his third minister on Thursday -- retired general Carlos Alberto dos Santos Cruz, who had been the government secretary and seen as a moderate voice.

That came on the same day Bolsonaro broke his silence to defend Justice Minister Sergio Moro, who has been accused of wrongdoing while serving as a judge in the sprawling Car Wash anticorruption investigation.

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