Slideshow ( 2 images )

BRASILIA (Reuters) - Brazil’s former president Luiz Inacio Lula da Silva has been charged by prosecutors who said the leftist politician was the mastermind behind the country’s biggest bribery scheme.

Lula, a founder of the Workers Party (PT) that controlled Brazil’s presidency from 2003 until last year, is already facing five separate trials on corruption charges with a ruling in the first expected by July.

Under Brazilian law, it is now up to a federal judge to decide if Lula will stand trial for the latest charges.

Prosecutors accused Lula of leading a scheme in which politicians and executives at state-run oil company Petrobras received bribes from companies seeking contracts for public projects.

Lula’s defense lawyers said in a statement that the new charges were “frivolous” and part of political persecution of the former leader who is leading opinion polls for next year’s presidential elections.

If Lula were convicted in any of the trials, and the ruling was upheld by a second court, he would be legally disqualified from running and likely go to prison.

Current Brazilian President Michel Temer is facing calls for his resignation over corruption and said he would not step down even if he was formally indicted by the Supreme Court. Temer took office a year ago after the ouster of Dilma Rousseff, who succeeded Lula.