With just over a month to go until Brazil’s presidential election, polls show that environmentalist Marina Silva has widened her lead over Dilma Rousseff to 10 percentage points.
It comes as government data shows the country has fallen into recession.
Gross domestic product dropped by 0.6 percent in the second quarter, mainly because of soft consumer spending.
Analysts say investors are also holding off, as they wait to see how the election affects the financial situation.
The slump in what was a robust economy gives more ammunition to Rousseff’s rivals, including Silva – who is tapping into the frustrations of many Brazilians.
But the president and her team say the downturn is not their fault and are questioning whether the country is actually in recession.
They blame the slowdown on a weakening global appetite for Brazil’s exports and a severe drought.