Brazil's Supreme Court on Monday sentenced a former presidential chief of staff to nearly 11 years in prison for his role in a congressional vote-buying scheme during the first two years of President Luiz Inacio Lula da Silva's 2003-2011 tenure.

Jose Dirceu's actions "put at risk the foundations of the democratic system itself," Justice Joaquim Barbosa said.

The stiff sentence reflects Dirceu's prominent role in the activities of the 24 other defendants convicted in Brazil's "trial of the century," the jurist said.

Dirceu spent two decades as the political right arm of Lula, founder of the Workers Party, or PT, which remains in power under President Dilma Rousseff.

Once seen as the natural heir to Lula, Dirceu was forced to resign as presidential chief of staff in the summer of 2005 after lawmaker Roberto Jefferson accused the PT of having bribed legislators of other parties to build the congressional majority that the government failed to obtain at the polls in 2002.

The scandal didn't stop Lula from winning a second four-year term in 2006 or from helping his anointed successor, Rousseff, to prevail in the 2010 presidential contest.

Also sentenced Monday was Jose Genoino, the PT chairman during the period of the bribes to lawmakers.

Genoino, a PT co-founder who was part of the armed resistance to Brazil's 1964-1985 military regime, received a prison term of six years and 11 months. EFE