Brazil's lower house of Congress opened final debate on Sunday ahead of a vote on impeaching President Dilma Rousseff amid chaotic scenes as rival deputies sang patriotic songs and scuffled in the chamber.
After party leaders completed their final statements, the 513 deputies were to vote on whether to send Rousseff to the Senate for possible trial. A two thirds majority, or 342 votes, were needed for the vote to pass.
"The session is open under the protection of God and in the name of the Brazilian people," said lower house Speaker Eduardo Cunha, a fierce opponent of Rousseff.
Deputies in the chamber shouted "There will be no coup!" and "Impeachment now!" as well as singing the national anthem and a famous patriotic song regularly sung at football games.
Then barely minutes after starting, the session descended into chaos with deputies scuffling, waving flags, and briefly unfurling a banner behind Cunha, reading "Out with Cunha!"
Rousseff is accused of illegally manipulating government accounts to mask the poor health of the budget in an election year. She says the accounting tricks were common practice in previous governments and do not amount to an impeachable offense.
Many in Brazil's Congress, notably Cunha, have faced criminal charges or investigations. Cunha is accused of stashing millions of dollars in bribe money in Switzerland.
The impeachment crisis has paralysed activity in Brasilia, just four months before the country is due to host the Olympics in Rio de Janeiro, and as it seeks to battle an epidemic of the Zika virus, which has been linked to birth defects in newborns.
While Rousseff herself has not been personally charged with corruption, many of the lawmakers who will decide her fate on Sunday have.
Congresso em Foco, a prominent watchdog group in Brasilia, says more than 300 of the legislators who will vote on Sunday - well over half the chamber - are under investigation for corruption, fraud or electoral crimes.
If Rousseff loses Sunday's vote, the Senate must decide whether there are legal grounds to hear the case against her, a decision expected in early May.
Should it agree to do so, Rousseff would be suspended from office and Temer would automatically take over.
Financial markets in Brazil have rallied strongly in recent weeks on hopes that Rousseff's dismissal would usher in a more business-friendly Temer administration. Sources close to the vice president told Reuters on Friday he was considering a senior executive at Goldman Sachs in Brazil for a top economic post.
Whoever governs the country in the coming months, however, will inherit a toxic political environment, a deeply divided Congress, rising unemployment and an expected contraction of 4 percent this year in the world's ninth largest economy.