Brazil awoke on Monday to deep political crisis after lawmakers authorized impeachment proceedings against President Dilma Rousseff, sparking claims by supporters that democracy was under threat in Latin America's biggest country.

Opposition deputies in the lower house of Congress needed 342 of the 513 votes, or a two-thirds majority, to send Rousseff's case to the Senate, which will now decide whether to open a trial. They reached that number near midnight on Sunday, after five hours of voting.

Wild cheering and a burst of confetti erupted from opposition ranks at the 342nd vote, countered by furious jeering from Rousseff allies in a snapshot of the bitter mood consuming Brazil just four months before Rio de Janeiro hosts the Olympics.