SAO PAULO (AP) -- Brazil's largest party abandoned President Dilma Rousseff's governing coalition Tuesday, making it tougher for her to survive mounting pressure in Congress for her impeachment.
The Brazilian Democratic Movement Party, known as the PMDB, said after a meeting that six Cabinet ministers belonging to the party as well as some 600 federal government employees who are members must step down. The announcement was made after more than 100 lawmakers approved the decision, according to the press office of Romero Juca, an influential senator.
"As of today in this historical meeting for the PMDB, the party withdraws from the base of the government of President Dilma Rousseff and no one in the country is authorized to hold any federal position in name of the PMDB," Juca said to loud cheers and applause after the decision was approved.
The session ended with chants calling for the end of Rousseff's Worker's Party and for Vice President Michel Temer to become Brazil's president. Temer, who is the leader of the Democratic Movement, would assume the presidency if Rousseff was impeached for breaking fiscal laws.
The break increases the chance that Rousseff, whose popularity has plunged amid Brazil's worst recession in decades and corruption scandals, will be impeached in the coming months.
"The exit of the PMDB, President Dilma's main ally, represents the end of the ruling coalition and greatly increases the chances of her impeachment, for her party is now a minority in Congress," said Carlos Pereira, a professor at the Fundacao Getulio Vargas, a top Brazilian university.
"PMDB's exit will definitely encourage smaller parties to follow its example and leave the coalition, forcing Dilma's government into a situation of political isolation," he added.
Brazilians have been staging wide protests demanding the president's impeachment and protesting the sprawling corruption scandal at state-run oil giant Petrobras that has been moving closer to Rousseff's inner circle. Rousseff, a former chairwoman of Petrobras' board, has not been implicated in the unfolding scandal at the oil company, which prosecutors say is the largest corruption scheme ever uncovered in Brazil.
Rousseff backers say impeachment is a power grab by opponents who themselves have been sullied by the probe into kickbacks and bribery at Petrobras.
"The law and the constitution foresee that to remove the president there must be a fiscal crime and there isn't one," said Afonso Florence, a leader in the governing Workers Party.
"That is why impeachment is a coup, but not only a coup against the president, but also against democratic legality."
The embattled leader will now search for new allies and will try to form a new government before the end of the week, Rousseff's chief of staff, Jaques Wagner, told reporters.
"The decision by the Democratic Movement party comes at a good time because it offers the president an opportunity to reconsolidate her government," Wagner said. "In other words, to start a new government."
A recent poll by the respected Datafolha agency says 68 percent of people surveyed want to see lawmakers vote to impeach Rousseff, but only 11 percent believe they would be better off under Temer.
Temer has been sullied by accusations he took part in the Petrobras corruption scheme as have the two other figures in line to succeed Rousseff — the heads of the lower house and the Senate, both of whom are also Democratic Movement members. All three deny any wrongdoing.
The leak last week of spreadsheets listing payments to nearly 300 politicians representing dozens of parties further inflamed widespread disgust with Brazil's entire political class. The spreadsheets were seized in the Petrobras case from the home of a top executive at one of Brazil's biggest companies and list politicians and their code names alongside monetary figures. Authorities are still investigating whether the sums constituted illicit payouts or were legal campaign donations.
David Fleischer, a professor emeritus of political science at the University of Brasilia, said the Democratic Movement's decision to leave the coalition will increase the number of anti-Rousseff congressmen on the impeachment committee in the lower house of Congress.
"Impeachment has become irreversible," Fleischer said. "The president has no other way out."