SAO PAULO, Brazil -- Brazil's political landscape was being redrawn Thursday, a day after a small plane crash killed a top presidential candidate less than two months before the election.

The death of politician Eduardo Campos in a plane that smashed into a white-collar neighbourhood in the port city of Santos is reshuffling the candidates and voter preferences, and could further complicate president Dilma Rousseff's re-election, analysts say.

Political observers say Campos' socialist party is expected to declare his running mate Marina Silva, one of the country's most popular politicians, as its presidential candidate in the coming days.

"If she runs, it becomes a more competitive race. It increases the likelihood of a runoff happening," said Joao Augusto de Castro Neves, Latin America director for the Eurasia Group consulting firm. "It would be a pretty close race to see who is going to be the runner up."

The other main candidate, Aecio Neves, has been showing in polls as a strong second choice after Rousseff. The election had been shaping up to be a two-candidate race, leaving Campos out of the runoff. But experts are now saying that the next polls could show Silva, a former Environment Ministry and presidential candidate, beating Neves, and possibly setting the two female politicians head to head in a second round.

"(Marina) could be the springboard needed to overcome the tragedy and become a viable candidate in a second round," wrote Paula Cesarino Costa, a columnist for Folha de S. Paulo.

The crash put campaigns on halt and politicians are avoiding any comments on the Oct. 5 race so they are not seen as insensitive to the deaths of 49-year-old politician, four of his aides and two pilots.

The 56-year-old Silva hasn't hinted that she will take the lead as the Brazilian Socialist Party nominee. Brazilian law gives parties 10 days to choose a substitute in the case of a candidate's death. The party could still choose another candidate, more loyal to the base, or decide not to run and support the president or her main opponent.

A longtime evangelical Christian, Silva surprisingly won 20 million votes when she ran for president as the Green Party candidate in 2010. An outsider of Campos' party, she joined his ticket last October after she was unable to set up her own party in time to run against for president.

Along with garnering a possible sympathy vote after the crash, some experts say Silva could exploit dissatisfaction among Brazilians. She gained a strong base after the mass protests that swept Brazil last year and won international praise for her efforts in helping preserve the Amazon rainforest as environment minister.

Rousseff, the hand-picked successor of former President Luiz Inacio Lula da Silva, has seen her popularity flag in recent months slowing economic growth, high taxes and poor public services -- although she has remained the strongest candidate. A survey by the Ibope polling agency released over the weekend said 38 per cent of those questioned supported Rousseff, while 23 per cent were for Neves and 9 per cent backed Campos.

Meanwhile, a day after the Cessna 560XL travelling from Rio de Janeiro to the city of Guaruja went down, firefighters and investigators were still picking through the wreckage. They were trying to recreate the path of the crash that damaged more than 10 buildings and also slightly injured at least five people. Officials have said the plane was trying to land in bad weather but a federal investigation was opened to determine the exact cause.