Brazil's leading opposition candidate Jose Serra on Saturday launched his bid for the presidency in October elections, proposing more efficiency, new trade deals and improved public transportation and security, according to Reuters. Serra, of the centrist PSDB party, also criticized high taxes in Latin America's largest economy and accused the current administration of President Luiz Inacio Lula da Silva of turning a blind eye on human rights abuses abroad. The PSDB, the right-wing Democratas, and the Popular Socialist Party declared their support for the veteran politician at an event in the capital Brasilia. "We are here today to renew our commitment to Jose Serra," Democratas president Rodrigo Maia told several thousand supporters at a packed convention center. Serra's main rival for the top job will be Dilma Rousseff of Lula's ruling, center-left Workers' Party. Serra, a 68-year-old trained economist, has a 9-point lead over Rousseff in an opinion poll two weeks ago. A former health minister and mayor of the city of Sao Paulo, Serra resigned as Sao Paulo state governor last week in line with election laws. Under the slogan "Brazil can do better" Serra proposed a more efficient and professional state apparatus that would allow for lower taxes but more investment. "Practicing fiscal austerity means doing more and better with the same resources," he said in a prepared speech. Neither Serra nor Rousseff are seen as breaking with the mostly market-friendly policies that have ensured economic stability over the past decade. But some investors prefer Serra for his party's centrist position and his experience. MORE GROWTH Brazil's economic growth was not sustainable with a "perverse combination" of high taxes, growing spending and a rising balance of payments deficit, Serra said. Brazil needed to significantly boost its investment in infrastructure, which was one of the lowest in the world. Pot-holed roads and crowded airports were a major brake on the economy, he said in a swipe at Rousseff, who headed the Lula administration's infrastructure investments. "Brazil's GDP could grow more -- 50 percent more -- if its infrastructure were adequate." Brazil also needed to pursue new exports markets more aggressively and negotiate more free trade deals, Serra said. "Do you know how many trade accords Brazil signed in recent years? One, and it still requires congressional approval. Where's the aggressive trade policy?" Serra, who was persecuted during military dictatorships in Brazil and Chile, criticized the Lula administration for an ambiguous stance on human rights abuses abroad. "Democracies don't have workers who disagree dying of a hunger strike," he said referring to Lula's recent description of a dying Cuban dissident as a common criminal. PSDB leaders have also criticized Lula's close ties to Iran, whose president visited Brazil last year. "Human rights are not negotiable," Serra said. SECURITY Serra also dwelled on health and public security issues, which opinion polls show are the Lula government's weakness. "What mother or father doesn't feel threatened by violence and drug-trafficking?." Drug-related violence rattles Rio de Janeiro and other cities frequently, killing thousands of people each year. Jacira Nazare, who distributed good-luck bracelets at the event, said she would vote for Serra, even though she backed Lula's reelection in 2006. "I haven't see the improvement I had hoped for where I live," she said, citing problems of insecurity and drugs in her neighborhood in the northeastern city of Salvador. Known for his often stiff demeanor and pedantic style, Serra appeared relaxed and reaped the occasional, spontaneous applause as he cracked jokes and told anecdotes of his life. But despite the fanfare, party leaders remained realistic, knowing that Rousseff will benefit from the president's huge popularity and a quickly rebounding economy. "It will be one of the most difficult elections of all time," PSDB president Sergio Guerra told supporters.