Brazil election: Players and policies

Voting in Brazil is mandatory for those aged between 18 and 70 and is done electronically

Until mid-August, Brazil's presidential election, due to be held on 5 October, appeared to be heading for a predictable outcome.

All polls gave a clear lead to incumbent Dilma Rousseff, but the sudden fatal accident of one of the main candidates has injected a big dose of unpredictability.

Why is the president's re-election suddenly in doubt?

Before the death of Mr Campos in a plane crash, Ms Rousseff had been well ahead in the opinion polls

Despite widespread dissatisfaction with the performance of her centre-left Workers' Party (PT), opinion polls suggested Ms Rousseff was well ahead of her two main rivals, Aecio Neves and Eduardo Campos.
It looked like Ms Rousseff would be re-elected by default as none of the other candidates seemed to stand out enough from Brazil's white political elite to capture the voters' imagination.
Then Mr Campos, the candidate for the Brazilian Socialist Party, died in a plane crash and his replacement, Marina Silva, emerged as a surprisingly strong contender.
The environmentalist from the Amazon was already a well-known politician, having come third in the 2010 presidential elections. Her humble background, mixed-raced ancestry and corruption-free credentials have set her apart.
In a recent poll, 25% of canvassed voters said they would support her in the first round, compared to 40% of canvassed voters who said they would back Ms Rousseff and 20% who said they would back Mr Neves, of the Brazilian Social Democracy Party.
While the poll gives the president a lead of 15 percentage points, a failure by her or any other candidate to get more than 50% of the votes would mean that the election goes into a second round.

How has Dilma Rousseff's presidency measured up?

Many Brazilians have been lifted out of poverty thanks to the government's social aid programmes

Statistics are in Ms Rousseff's favour.
During her tenure, unemployment has been lower than under any of her predecessors, at about 5%.
The minimum monthly wage (R$724; $304; £183) has increased despite the financial crisis and the number of undernourished Brazilians has fallen by more than 80% in the past decade, according to the UN.
To improve access to healthcare, 14,000 doctors have been drafted in from Cuba. Other social programmes have further improved the life of lower income households, a fact that even rival candidates have acknowledged.