The survey found only 30 per cent of respondents rated Rousseff’s government as “great/good”, a sharp fall from the 57 per cent who gave it that rating three weeks ago before the demonstrations began.
Almost 5,000 people were interviewed for the poll on 27 and 28 June. It was published yesterday in the country’s biggest newspaper, Folha de S Paulo. It said Rousseff’s rating suffered the biggest drop in presidential approval since a 1990 fall for then-president Fernando Collor de Mello, who was forced from office because of a corruption scandal.
Protests were first held in response to an increase in the cost of public transport but have expanded to include a variety of causes including government corruption, poor public services and the vast amount of money to be spent on next year’s World Cup football tournament and the 2016 Olympics in Rio.
The poll showed eight in ten people supported the ongoing protests as a way of letting government officials know about their displeasure at a range of issues.
Political watchers said Rousseff’s popularity drop was to be expected in the face of the biggest protests the 197 million-person nation has seen in two decades.
Some commentators said it was not just the government that people were protesting against, but politicians in all parties.
Pedro Arruda, a political science professor at the Catholic University of Sao Paulo, said: “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.
“If polled, the unpopularity would be of all politicians. The people are protesting all the parties.”
Throughout the protests, the country has hosted the Confederations Cup football tournament, which is seen as a warm-up to next year’s World Cup.
The unrest has grown to such a level that Rousseff and other political leaders have reportedly decided not to attend today’s final match between Brazil and Spain.
Thousands of demonstrators are expected to protest outside the iconic Maracana stadium in Rio where the final is being held.
Meanwhile, users of social networks reported rumours of a general strike being held tomorrow, with posts saying it would hit every state.
However, representatives for 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 11 July, when employees will work to rule.
Rousseff is expected to deliver a formal proposal to Congress tomorrow on a political reform plebiscite she wants held in the coming months. She has not yet released any details on what political reforms she will suggest or when a plebiscite would occur.
Earlier this week, the president announced $23 billion (£15bn) in transport investments.
She said her government would prioritise improvements in fiscal responsibility, controlling inflation, political reform, healthcare, public transport and education.