Brazilian president Dilma Rousseff's support plummets in wake of protests Demonstrators in Sao Paulo, Brazil, carry a "Dilma out" sign referring to President Rousseff. Dilma Rousseff's approval rating sank by 27 percentage points in the last three weeks, the strongest evidence yet that the recent wave of street protests sweeping Brazil poses a serious threat to the president's likely re-election bid next year. The share of people who consider Rousseff's administration "great" or "good" plummeted to 30% from 57% in early June, according to a Datafolha opinion poll published in newspaper Folha de S Paulo on Saturday. The drop was the sharpest for a Brazilian leader since 1990, when Fernando Collor outraged the population by freezing all savings accounts in a desperate attempt to stop hyperinflation. Two years later, Collor resigned from the presidency as Congress began impeachment proceedings against him over corruption allegations. Until recently, Rousseff enjoyed some of the highest approval ratings of any leader in the western world, largely thanks to record low unemployment. But her popularity started to slip in early June as rising consumer prices began to eat away at Brazilians' purchasing power, a sure recipe for trouble in a country with a long history of runaway inflation. Then came the nationwide street demonstrations of the past few weeks which have sent shockwaves through Brazil's political establishment. While the protests have not been directed at a single leader or party, widespread discontent with a ruling class that is seen as self-serving and corrupt is eroding the popularity of politicians at all levels, including Rousseff. The Datafolha poll was the first taken since more than a million Brazilians poured on to the streets in recent weeks to protest against a litany of grievances, from corruption and poor public services to outrage at billions of pounds in taxpayers' money being spent to host the 2014 World Cup. The president's approval rating fell sharply in all regions of the country, the poll showed. In the north-east, the birthplace of her popular predecessor Luiz Inácio Lula da Silva and a stronghold of the ruling Workers party, the share of people who view the administration favourably sank to 40% from 64% in a poll on 8 June. The poll also asked Brazilians if they were in favour of the protests, the largest to hit Brazil in two decades. Eighty-one percent of respondents said they support the demonstrations. Asked if the protests had resulted in positive changes, 65% said yes. The unrest has prompted a flurry of promises to improve public services and other measures aimed at quelling the protests. In the past week alone, Brazil's Congress voted on a battery of bills promoting issues popular with the protesters, and the supreme court ordered the arrest of a lower house representative convicted of corruption. Rousseff shocked Brazil on Monday by proposing a constituent assembly to overhaul the country's political system, but withdrew the plan a day later after it met widespread opposition, even from within her own party. She is now seeking congressional support for a non-binding referendum to ask Brazilians how they would like to see the political system changed. In the Datafolha poll, 68% of respondents said they backed the idea of a referendum. The drop in Rousseff's popularity comes at a delicate moment for Brazil's economy, which barely expanded last year and relies on an ambitious agenda of infrastructure projects to return to sustained growth. The approval rating of Rousseff's economic team, led by the finance minister, Guido Mantega, and the central bank president, Alexandre Tombini, dropped to 27% from 49%. The Datafolha poll, which was conducted on 27-28 June, surveyed 4,717 people and has a margin of error of plus or minus two percentage points.