By Anthony Boadle
BRASILIA (Reuters) - Brazilian President Dilma Rousseff's approval ratings are recovering from a wave of popular discontent in June and she has broadened her lead over other possible contenders in next year's election, a poll published on Tuesday showed.
But her negative numbers remain high enough to force a run-off vote that could complicate a re-election bid.
The number of Brazilians who approve of her government's performance rose to 38.1 percent at the start of this month from 31.3 percent in July, according to the poll commissioned by private transport sector lobby CNT and done by MDA Pesquisa.
Those who disapprove of the government's performance dropped to 21.9 percent from 29.5 percent in July, the survey said.
Rousseff's personal approval rating, which was in the high 70's before massive street protests shook Brazil in June, recovered to 58.0 percent from 49.3 percent in July.
Hundreds of thousands of Brazilians took to the streets in an outburst of anger against the country's politicians of all stripes for corruption, mismanagement of government money, the high cost of living and poor public services.
Rousseff has scrambled to improve public transportation, health and education services, while pushing for reforms to make the country's political establishment more accountable.
The CNT/MDA poll showed that two in every three Brazilians believe her government has moved to meet the demands of the demonstrations that have subsided since peaking in June.
A controversial program to improve medical attention in remote and poor parts of Brazil by bringing foreign doctors, mainly from Cuba, was backed by 73.9 percent of those polled.
But 75.9 percent of Brazilians think inflation has not been brought under control, the poll showed.
The poll confirmed a trend by other recent surveys that point to a recovery in Rousseff's popularity as she head towards a widely expected re-election bid in October 2014.
"Rousseff is beginning to show a recovery. Her personal approval rating rose about 8 percent, approval of her government rose about 7 percent and voter intention is up by 3 percent," said MDA pollster Marcelo Costa Souza.
Rousseff's negatives have come down, with 41.6 percent of those polled saying they would never vote for her, down from 44.7 percent in July. That, says Costa Souza, is not enough to avoid a second-round vote with an uncertain outcome.
Rousseff's main potential rival, environmentalist Marina Silva, continues to gather steam. Voting intentions for Rousseff increased to 36.4 percent from 33.4 percent in July, compared to 22 percent for Silva, who improved from 20.7 percent in July.
Support for the likely candidate of the main opposition party PSDB, Aecio Neves, remained unchanged at 15.2 percent, while the governor of Pernambuco state, Eduardo Campos, slipped to 5.2 percent from 7.4 percent in July.
Silva, a former environment minister, is not identified with Brazil's traditional political establishment and the recent protests have boosted her. Silva came third in the 2010 election, winning 20 million votes as candidate for the Green Party. She has since founded a new party, but it is not certain that she can register it in time for the 2014 election.
The CNT/MDA poll of 2,002 people was conducted between August 31 and September 4, and has a margin of error of 2.2 percentage points.
(Editing by Doina Chiacu)