Brazil's Senate is debating whether President Dilma Rousseff should face a full impeachment trial.
The majority of the senators have already said they will vote against the president.
If this is confirmed in a vote to be held later, Ms Rousseff will be automatically suspended from office.
She is accused of illegally manipulating finances to hide a growing public deficit ahead of her re-election in 2014, which she denies.
Ms Rousseff made a last-ditch appeal to the Supreme Court to stop proceedings, but the move was rejected.
What's happening now?
A lengthy debate lasting all night preceded the actual vote. The Senate session opened 20 hours ago.
There are a total of 81 senators in the upper house, but only 71 were present. By 05:45 local time (08:45GMT), all 71 senators present had spoken. Final speeches were expected to last 30 minutes before the vote took place.
Of those, 49 - a majority - backed the impeachment trial in their speeches, 20 rejected it and two did not give an indication as to how he would vote.
The session has been a lot less passionate than that in the lower house on 17 April in which a overwhelming majority of the 513 lawmakers voted in favour of the impeachment proceedings going ahead.
The members of the lower house cited all kinds of reason for their decision with many saying they were doing if "for my family", "for God" or simply "the country".
What do Dilma Rousseff's critics say?
In the Senate, the arguments given for the impeachment trial have been mainly economic.
Many blamed President Rousseff for the dire straits the country's economy is in.
Brazil is suffering from its worst recession in 10 years, unemployment reached 9% in 2015 and inflation is at a 12-year high.
Senator Aecio Neves, who lost to Ms Rousseff in the 2014 presidential election, said: "Populist governments always act with fiscal irresponsibility and when they fail they appeal to the old 'us vs them' argument."
"The poorest and most vulnerable in society, who need the government support the most, always end up paying the bill," he added.
Mr Neves said he would vote for an impeachment trial.
Ataides Oliveira of the opposition PSDB party said that "today, we're going to retrieve the country from the hands of the PT (Ms Rousseff's Workers' Party) and give it back to the Brazilian people".
Former football player turned senator Romario said Brazil was in "a very serious crisis" before revealing that "after much thought" he had decided to back her impeachment trial.
Senator Alvaro Dias said that "they [the government] have already stolen so much from us, don't let them steal our hope for a better future".
What do Dilma Rousseff's backers say?
Those arguing against the impeachment trial said it was tantamount to a coup d'etat.
Senator Telmario Mota said that "today we are seeing an attempted takeover of power which calls itself impeachment".
He added that the impeachment proceedings were "born of revenge, hatred and revenge".
Senator Fatima Bezerra from the Workers's Party called the proceedings "a farce". "Those who back this coup d'etat won't ever be forgiven," she warned.
Senator Vanessa Grazziotin of the Communist Party of Brazil said the impeachment process was just a pretext to put an end to the social programmes the Workers' Party had brought in.
Former President Fernando Collor de Mello, who himself faced impeachment proceedings in 1992, gave a lengthy speech about the injustice he said had been committed against him but failed to give an indication of where he stood on Ms Rousseff's impeachment.
If the vote goes against her, Ms Rousseff will be replaced by Vice-President Michel Temer while the impeachment trial lasts.
Her chief of staff, Jaques Wagner, said Ms Rousseff was "outraged by the injustice committed against her, but standing firm awaiting the Senators' decision.
She has promised to fight to the end.
"I will not resign. That never crossed my mind," she said during a speech on Tuesday.