The main suspect in Brazil's biggest ever corruption trial is Jose Dirceu, chief-of-staff of ex-president Luiz Inacio Lula da Silva, who is not on trial.

Thirty-seven other defendants, which include ex-ministers, lawmakers, businessmen and bankers, are due to appear in Brasilia during what has been dubbed "the trial of the century" by the Brazilian press.

Lula's Workers Party (PT) and the ruling coalition at the time are alleged to have been embroiled in the scandal known as mensalao, which translates as big monthly payments, as sums of up to $10,000 (8,200 euros) allegedly changed hands.

PT lawmakers allegedly offered bribes to members of Congress to secure their votes. Prosecutors allege that the bribe money was siphoned off from the advertising budgets of state-owned entities and the channelled into a company owned by businessman Marcos Valerio de Souza, who is one of the defendants.

Over 1,000 charges

There are 1,089 charges, which include corruption, money-laundering, misuse of public funds, embezzlement and conspiracy in what Attorney General Roberto Gurgel called "the most daring and outrageous corruption scheme and embezzlement of public funds ever seen in Brazil."

"I believe the Supreme Court will let justice prevail. And, from the point of view of the prosecution, justice means that they will all be convicted," Gurgel said in an interview ahead of the trial.

Dirceu's lawyer has denied the charges, saying there was never any mensalao.

Observers also see the trial as a watershed. "It's a change of game. Brazilians are going to see someone accused of corruption really go to trial, maybe get convicted," David Fleischer, a political scientist at the University of Brasilia told the Associated Press.

"Impunity no longer operates. This is going to turn a page. In the future, politicians will be very careful, much more cautious about how they do things," Fleischer said.

ng/ipj (AP, AFP, dpa)