Michel Temer used to be known in Brazil as a behind-the-scenes operator, but that was before he pulled the trigger on a masterful plot to topple his boss, President Dilma Rousseff, and take her job.

Brazil's Senate held a marathon debate Wednesday on suspending and impeaching President Dilma Rousseff, whose hours in office appeared to be numbered as the Supreme Court rejected her bid to halt the proceedings.

Even Rousseff's allies said she had no chance of surviving the Senate vote, which could end 13 years of leftist rule in Latin America's biggest country.

The impeachment of Brazil's President Dilma Rousseff looked set to go ahead on Tuesday, after the interim speaker of the lower house said he had reversed his earlier annulment.

In the latest twist to the country's spirling political crisis, local media said Waldir Maranhao had "reversed the decision" to cancel the April vote by lawmakers that had first begun the process.

President Dilma Rousseff voiced confidence Friday that Brazil's people will "be able to prevent any setbacks" to democracy as she battles a bid to impeach her.

"Brazil is a great country endowed with a society that was able to overcome authoritarianism in the past," Rousseff said at the United Nations during a ceremony for the signing of the Paris climate deal.

Australian Prime Minister Malcolm Turnbull was Monday handed his trigger to call July elections after the Senate for a second time rejected government legislation to re-establish a construction industry watchdog.

Turnbull, who wrested the leadership from conservative Liberal Party colleague Tony Abbott in September, has threatened to hold national polls for both houses of parliament on July 2 unless the Senate passed two stalled bills relating to unions.

The steel wall cutting across the heart of Brasilia does more than separate rival protesters for Sunday's Congress vote on impeaching President Dilma Rousseff -- it now symbolizes the divide tearing through Brazil.

Authorities installed the kilometer (half-mile) long barrier in front of Congress to prevent disturbances when an estimated hundreds of thousands of people gather for the controversial vote.

A gas explosion ripped through an apartment complex north of Rio de Janeiro early Tuesday, killing five people and injuring 13, firefighters said.

Civil defense officials said the explosion occurred at 5:00 am local time (0800 GMT) and may have resulted from a leak in a gas line.

Brazilian President Dilma Rousseff's top lawyer will present final arguments before an impeachment committee Monday at the start of a crucial two weeks in the embattled leader's bid to stay in power.

Solicitor General Jose Eduardo Cardozo was due to face the cross-party committee for the last time before it votes on whether to recommend Rousseff face trial for allegedly illegal accounting practices.

Allies of embattled Brazilian President Dilma Rousseff horse-traded in Congress on Wednesday in a frantic bid to find enough votes to ride out an impeachment drive after her main coalition partner quit the government.

A months-long crisis reducing Latin America's biggest country to political paralysis ahead of the Rio Olympics peaked Tuesday when the centrist PMDB broke its alliance with the leftist Rousseff's Workers' Party.

Brazilian police arrested dozens of corruption suspects Tuesday as the scandal around state oil company Petrobras continued to escalate, and with it the threat to President Dilma Rousseff's government.

Federal police said they had uncovered a "professional and institutionalized" bribe-paying system at construction giant Odebrecht, one of the companies implicated in a multi-billion-dollar corruption scandal that has rocked the Brazilian government.