The speaker of Brazil's lower house of Congress has opened impeachment proceedings against President Dilma Rousseff, BBC News reports.
The process is based on allegations Rousseff broke the law in managing last year's budget, Eduardo Cunha said.
Despite re-election last year, her popularity has slumped amid a corruption scandal involving the state-owned oil giant, Petrobras.
"I was outraged by the decision," said Rousseff in a televised speech. "I haven't committed any wrongful act," she added.
Rousseff, who earlier called an emergency cabinet meeting, said she was confident that the impeachment motion would be rejected.
Two-thirds of the lower house must approve the process for it to proceed.
The governing coalition has a majority in the lower house of Congress.
The defeated opposition candidate in last year's presidential election, Senator Aecio Neves, has tweeted that he supports the impeachment request.
"Everyone in the country must obey the law, especially the president," he wrote.
