Allegations range from tax evasion by the Central Bank president to embezzlement at the state-run Banco do Brasil. The government of President Luiz Inacio Lula da Silva has dismissed the charges as "political intrigues" of the opposition and sensationalism by reporters on the eve of municipal elections.
Both government and the PT have closed ranks around Central Bank President Henrique Meirelles, accused by a number of magazines of committing fiscal irregularities before becoming president of the Central Bank in 2003.
The Lula administration and party displayed much the same zeal in defending state-run Banco do Brasil President Cassio Casseb, whose reputation has been tarnished in another case.
Casseb has yet to clarify why Banco do Brasil last month spent 70,000 reais (around $23,500) to buy tickets to a musical event being held as a PT fundraiser.
"The first conclusion is that the PT is getting a taste of its own accusatory poison," wrote Folha de Sao Paulo columnist Eliane Catanhede.
She did, however, note an important difference: during the two administrations of Fernando Henrique Cardoso (1995-2002), heads rolled as a result of the Socialists' accusations, but "Lula's government has issued orders to stand up to the charges." According to the weekly newsmagazine Veja, Casseb tried to quit twice last week, but Lula and Finance Minister Antonio Palocci refused to accept his resignation, while Meirelles said he has no plans to leave office - much to the relief of both the government and the nation's financial markets, which embrace his orthodox monetary policies.
The latest revelation concerns PT treasurer Delubio Soares, whose family bought lands in the central Brazilian state of Goias two months ago - at four times less than market value, O Globo said.
Soares is in charge of raising money for the purchase of a building meant to house new PT headquarters in Sao Paulo. The paper says that businessmen and even some party members have complained of being hounded to contribute to the project.
Although the PT championed clean government and became self-appointed guardian of the "national patrimony" while in the opposition, the government is now hard pressed to separate the public from the private, even in such simple matters as incorporating the party's symbol of a star into the design of the gardens of the presidential palace - the patrimony of the entire nation.
The scandals date back to February, when it was learned that Chief of Staff Jose Dirceu, considered Lula's right-hand man, had taken kickbacks from operators of the country's ubiquitous bingo parlors. The government blocked efforts to launch a Congressional probe of the case.
"The ethical standards the PT created before were high, higher than those the government currently puts into practice," Catanhede observed in her Sunday column.