His main campaign message has been that a change in government will boost the business sector and consumer confidence, leading to resumed growth in 2015 that will be in turn reinforced by a return to fiscal austerity and a more aggressive anti-inflation policy.

Neves also accused Finance Minister Guido Mantega of using "creative accounting" to conceal fiscal problems and of being too soft in fighting inflation.

Rousseff, who is seeking a second four-year term, defended her government's performance, saying that Brazil's current unemployment is at its lowest level of 5 percent, and the minimum wage is adjusted annually to keep up with inflation and reflect economic growth to guarantee the purchasing power of Brazilian workers.

She has pledged to reform the tax system, revamp her treasury team, and promote domestic consumption, arguing that Brazil's slower growth is the result of lower external demand due to the international economic crisis.

Rousseff's economic team said that this year's higher inflation rate was sparked by shortages resulting from drought in parts of the country.

Her campaign team accused Neves of planning a return to the fiscal policies implemented by the Social Democratic government of Fernando Henrique Cardoso between 1995 and 2003, which raised interest rates to fight inflation, and at the same time benefit the financial sector.

The incumbent's camp also defends its implementation of the macroeconomic triad, forecasting that this year's fiscal surplus, projected to be between 0.5 and 1 percent of gross domestic product (GDP), can be increased next year to between 2 and 2.5 percent of GDP.

Rousseff is confident that as from next year, the economy will begin to feel the results of major infrastructure investment made this year in airports, ports and highways.

The government has built the foundations for a "new cycle of development," thanks to significant investment in the energy sector through state-owned banks, Rousseff's camp has said.

Brazil's middle class is the key to the race, as they are divided over Rousseff's transformative social policies and their number is increasing rapidly.

The candidates will have to battle for the new middle class if they want to win the runoff, analysts said.