Brazil's Rousseff picked by party for tough election October 5

Brazil's President Dilma Rousseff gestures while speaking during the national convention of her Workers' Party (PT) in Brasilia June 21, 2014. REUTERS/Joedson Alves

BRASILIA (Reuters) - Brazil's ruling Workers' Party formally nominated President Dilma Rousseff on Saturday to run for re-election in October in what is shaping up to be its toughest race since winning power in 2002.

Rousseff's popularity is falling because of Brazil's high cost of living and slowing economy, and she was jeered at the opening game of the football World Cup last week.