The Supreme Court in Brazil has found a top aide of the former Brazilian president, Luiz Inacio Lula da Silva, guilty of corruption.
Jose Dirceu, who was the president's chief of staff from 2003 to 2005, had been accused of setting up a scheme that used public funds to buy support from opposition parties in parliament.
He denies the scheme ever existed and said the allegations were political.
The former president is not implicated in the scandal.
The former head of Lula's Workers Party, Jose Genoino, and its treasurer, Delubio Soares, were also convicted and are also facing a jail sentence.
A total of 10 Supreme Court judges are due to return verdicts in the case.
A majority of them have found the three men guilty.
Mr Dirceu is a former left-wing rebel who fought the military government in the 1970s and was eventually sent to exile in Cuba.
He says right-wing media and politicians fabricated the allegations to try to bring down the Lula government.
The scandal became known in Brazil as Mensalao or the "Big Monthly" allowance.
The central allegation is that illegal payments and benefits were paid to congressmen in return for support for the government in crucial votes.
The case, with 37 defendants, is seen as a key test of Brazil's ability to hold its politicians to account for corruption.
Some of the defendants, who include politicians and business executives, say the scandal is being exploited by opposition politicians and sections of the media.
They say that the scheme was simply a way of paying off campaign debts which, while illegal, is common in Brazilian politics.
Others deny any involvement in buying political support.
A majority of the judges have already rejected claims by the defence that no vote-buying scheme existed.
Lula is not directly implicated in the case and has denied any knowledge of the scheme.
He left office at the end of 2010 with huge approval ratings, and remains a popular figure in Brazilian political life.