Brazilian President Luiz Inacio Lula da Silva widened his lead to 20 points in the opinions polls less than two weeks before the October 29th presidential runoff.
A recent scandal over a dossier to smear opposition candidates involving Mr Lula's Workers' Party prevented him from winning the first round on October 1st, and rival Geraldo Alckmin has since stepped up attacks on him to little avail so far.
A survey by the Datafolha polling firm showed Mr Lula, Brazil's first working-class president who has huge support from the country's poor, would win 60 per cent of the valid votes, compared with 56 per cent in a poll released last Wednesday.
Mr Alckmin, a former Sao Paulo state governor and a centrist favoured by many business leaders, was on 40 per cent in the poll, down from 44 per cent last week.
"Lula's campaign calls on people not to swap something certain, which they have with this government, for [something] dubious, and that seems to be working," said Carlos Lopes, a political analyst with the Santafe Ideias e Communicacao consultancy firm.
"As for Alckmin... it looks more and more like he needs a new scandal to be able to recover in polls," Mr Lopes added.
Social welfare for the poor and tame inflation are among the strengths of Mr Lula's government, although the opposition says economic growth has been only modest.
Brazil's Central Bank last month cut its 2006 growth forecast to 3.5 per cent from 4 per cent, and Brazil lags other emerging countries, including its Latin American neighbours.