Weeks after being removed as Brazil's president, Dilma Rousseff is calling the prosecution of her predecessor on corruption charges another attack on the nation's democracy.

Rousseff says Brazil is suffering from a "process that is systematically breaking the constitution."

She spoke in support of her mentor, former President Luiz Inacio Lula da Silva, a day after a federal judge ruled that he must stand trial on corruption and money-laundering charges. A conviction could ruin his chances of running for president again in 2018 and returning the leftist Workers' Party to power.

Prosecutors accuse Silva of taking bribes from a construction company in exchange for contracts with Brazil's big state-run oil company Petrobras.

Rousseff spoke Wednesday at a rally for Rio de Janeiro mayoral candidate Jandira Feghali.