BRASILIA (Reuters) - Two of Brazil's most popular opposition leaders joined forces on Saturday in an unexpected alliance that shakes up next year's election and could pose a major challenge to President Dilma Rousseff at a time when the economy is sputtering.
Marina Silva, a colourful former environment minister who was running second in polls for next year's presidential vote, said she was setting aside her own presidential ambitions to join the centre-left PSB Party and support its candidate, Pernambuco state Governor Eduardo Campos.
