Incumbent leader Dilma Rousseff has her eye on a second term as Brazil heads to the polls in the presidential elections.

It has been one of the most volatile campaigns in decades with the death of one candidate and a surge in support for his replacement making it likely to go to a second-round.

A third candidate has now emerged as a likely contender to Rousseff, the pro-business social democrat Aecio Neves who is now polling in second place. He promises to revive the economy after four years of sluggish growth. Should Rousseff not receive the 50 percent necessary to win outright, it would go to a run-off on October 26th.

Environmentalist candidate Marina Silva had been the hot contender until Saturday’s polls showed a drop in her support. She took over from her socialist running mate Eduardo Campos, who died in a plane crash in August.

With a result too close to call, Brazilians were queueing up to exercise their democratic right at 450,000 polling stations across the country. The use of electronic booths means the results are expected just hours after polls close in some states around midnight in Central Europe.