Public approval of Brazilian President Dilma Rousseff’s government has suffered a steep drop in the weeks since massive protests broke out across this country, according to the first nationwide poll released in Brazil since the unrest began.

Published Saturday by Folha de S.Paulo, the country’s biggest newspaper, the Datafolha survey found 30 percent of respondents rated Rousseff’s government as “great/good,” a sharp fall­­off from the 57 percent who gave it that rating three weeks ago, before the demonstrations began.

Datafolha interviewed 4,717 people on June 27-28, and the poll has a margin of error of 2 percentage points.

The firm said Rousseff’s rating suffered the biggest drop in presidential approval since a 1990 fall for Fernando Collor de Mello, who was forced from office within two years because of a corruption scandal.

Beginning in mid-June, the protests had at first targeted transportation fare increase but quickly expanded to a variety of causes, including government corruption, high taxes, poor public services and the billions of dollars spent for next year’s World Cup soccer tournament and the 2016 Summer Olympics in Rio de Janeiro. The Datafolha poll showed that 81 percent of respondents supported the protests.

Political watchers said Rousseff’s popularity drop was to be expected in the face of the biggest protests in this country of 197 million people in two decades. But it still wasn’t clear whether opposition politicians could take advantage of Rousseff’s problems, as she gears up for reelection next year.

“The protest movement that began two weeks ago isn’t necessarily a movement against the [ruling] Workers Party nor Dilma personally. It’s a protest against the entire ruling class,” said Pedro Arruda, a political science professor at the Catholic University of Sao Paulo. “If polled, the unpopularity would be of all politicians. The people are protesting all the parties.”

For Rio Mayor Eduardo Paes, the demonstrations have underscored the “institutional crises” affecting the country’s political parties.

“Which party has a good image?” he asked in an interview in Saturday’s edition of Folha de S.Paulo. “Only the one not yet been born. We cannot sit back and think there is nothing more to be done because we have become a democracy, pulled 40 million people out of poverty and enjoy high employment rates.”

Throughout the protests, the country has been host of the Confederations Cup soccer tournament, which is seen as a warm-up to next year’s World Cup. But the unrest has escalated to such a level that Rousseff and other political leaders have reportedly decided not to attend Sunday’s final match, which would be seen as a major embarrassment after they had showcased the country’s hosting of such mega-events as proof that Brazil had finally arrived on the global stage. Demonstrators are expected to turn out around Rio’s Maracana stadium, where the Brazilian and Spanish teams will meet.

Meanwhile, social networks were abuzz with rumors of a general strike Monday, with posts saying it would hit every state. But representatives of Brazil’s two biggest unions, the Central Workers Union and Union Force, said they knew nothing about such a strike but were planning a national work slowdown for July 11.

Rousseff is expected to deliver a formal proposal to Congress on Monday on a political reform plebiscite she wants held in the coming months.

Earlier in the week, the president announced $23 billion in transportation investments. In addition, she said her government would prioritize improvements in fiscal responsibility, controlling inflation, political reform, health care, public transport and education.

— Associated Press