"We are a government that does not tolerate corruption and we have the duty and obligation to fight impunity and corruption," she said in the wake of massive protests against her administration.
The package includes bills to criminalize under-the-table campaign contributions, seize property from government officials who cannot document its origin and bar anyone without a clean criminal record from serving in public office.
Rousseff is reeling from nationwide demonstrations against her that drew hundreds of thousands of Brazilians into the streets Sunday.
The left-wing leader has presided over a sharp slowdown in the world's seventh-largest economy and rising inflation, as well as the scandal at Petrobras, whose board she chaired during much of the period under investigation.
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Prosecutors say the state-controlled oil giant awarded inflated contracts to some of the country's biggest construction companies over a 10-year-period, generating a flood of dirty money used to bribe Petrobras officials and pay off politicians.
Among those charged is Workers' Party treasurer Joao Vaccari, accused of receiving huge bribes that he insists were legal campaign donations.
Rousseff, 67, has not been personally implicated in the scandal, and the Supreme Court today rejected an opposition request to investigate her.
But her popularity has taken a beating.
Sixty per cent of those surveyed in today's poll said they believed the country's economic situation was worsening, against 15 per cent who thought it would improve -- the most negative result since polling firm Datafolha began asking the question in 1997.