The speaker of Brazil's lower house of congress on Friday strongly denied newly filed charges of corruption and said he won't resign from office.

Attorney General Rodrigo Janot filed the charges Thursday against Chamber of Deputies speaker Eduardo Cunha and former President Fernando Collor, who is now a senator. Janot said the two men took part in the sprawling corruption scheme at state-run oil company Petrobras in which billions in bribes were allegedly paid.

In a meeting with union leaders in Sao Paulo on Friday, Cunha said there was not "the slightest chance" he will resign as speaker of the house.

"I have done nothing wrong and they have no evidence against me," Cunha said.

"Resignation has never been, or will it ever be, part of my vocabulary," he added.

On his Facebook page, Cunha said, "My conscience is clear and I will continue as Speaker of the Chamber of Deputies with same candor and independence of always."

Prosecutors said in a statement that Cunha is accused of accepting $5 million in bribes between 2006 and 2012 in connection with the construction of two Petrobras drilling ships. He is charged with corruption and with money laundering.

No details in the case against Collor were made public. The prosecutor's office said that was because it is based on accusations from an active informant and revealing details could jeopardize the investigation.

Collor told Brazilian media on Thursday that he was not guilty of any wrongdoing.

In the early 1990s, Collor became Brazil's first freely elected president in nearly three decades after a military dictatorship. But he resigned in 1992 just before the Senate impeached him over allegations he received millions from a slush fund run by his former campaign treasurer.

The charges against the two men have been filed with the Supreme Court, which must now decide whether they will go on trial. Under Brazilian law, charges against federal congressmen and other top government officials can only be filed and judged by the Supreme Court, which can take years to rule on such cases.

Prosecutors allege that some of the money from the kickback scheme at Petrobras made its way into the campaign coffers of the governing Workers' Party and its allies, as well as into the hands of dozens of lawmakers under investigation.

President Dilma Rousseff, whose approval ratings are in the single digits amid the scandal and economic problems, has not been accused of any wrongdoing, although she served as chairwoman of the Petrobras board during several years as the scheme played out.

Thousands of Brazilians turned out for rallies across the country on Thursday to voice support for the president, but their numbers were smaller than demonstrations on Sunday in which protesters called for Rousseff's resignation or impeachment.