In a session less electric than expected, Brazil’s suspended president proclaimed her innocence at her impeachment trial Monday, branding her vice president a "usurper," calling the drive to oust her a "coup" and warning senators that history will judge them harshly if they oust a democratically elected leader on false charges. 

Dilma Rousseff's much anticipated appearance before senators who will decide this week whether to permanently remove her from office was characterized by the same defiance she has shown throughout an impeachment process that has divided Latin America’s most populous nation. But it was also more civil than the three previous impeachment trial sessions, when lawmakers from both sides got into heated exchanges.

After 12 hours, she was still answering questions from senators late Monday night.

"I know I will be judged, but my conscience is clear. I did not commit a crime," Rousseff told senators who listened intently, in contrast to the chamber's usual raucousness.

In the middle of her second term, the left-leaning leader has been accused of breaking fiscal rules in 2015 to hide problems in the federal budget. She has denied any wrongdoing.

Rousseff reminded those in attendance that she was reelected in 2014 with more than 54 million votes, asserting that at every moment since she has followed the constitution and sought to do what was best for Brazil.

Brazil’s first female president is a former guerrilla fighter who was jailed and tortured during the country's dictatorship, and Rousseff drew a connection between her past and the situation today.

"I can’t help but taste the bitterness of injustice," she said.

During her 30-minute opening speech, Rousseff argued that in early 2015 opposition lawmakers began creating a climate of instability by refusing to negotiate and throwing what she called "fiscal bombs" in the face of the government's declining revenues as the once booming economy continued its slump.

She said the impeachment process had exacerbated the recession in Latin America’s largest economy, and she blamed the opposition, which has argued that she has to be removed for the financial climate to improve.

Rousseff blasted interim President Michel Temer as a "usurper." Her vice president turned arch-enemy, Temer took over when the Senate voted in May to impeach and suspend Rousseff for up to 180 days while a trial was prepared. He will serve out Rousseff's term until December 2018 if she is removed, but still faces risks of having his mandate cancelled at Brazil’s top electoral court.

Referring to Temer, Rousseff said Brazilians would never have elected a man who named a Cabinet of all white men in a country that is more than 50 percent non-white. The Cabinet that Temer put in place has been roundly criticized for its lack of diversity, and three of his ministers were forced to step down within a month of taking office because of corruption allegations.

Rousseff asserted she paid a price for refusing to quash a wide-ranging police investigation into the state oil company Petrobras, saying corrupt lawmakers conspired to oust her to derail the investigation into billions in kickbacks at the oil giant.

The investigation has led to the jailing of top businessmen and politicians, including in her Workers' Party. But they have plenty of company: Watchdog groups estimate 60 percent of the 594 lawmakers in both chambers are being investigated for wrongdoing, many for corruption related to the Petrobras probe.

Rousseff said it was "an irony of history" that she would be judged for crimes she did not commit, by people who were accused of serious crimes.

"I ask that you be just with an honest president," she said, her voice cracking with emotion. Her voice also changed when she made a reference to "the betrayal, the verbal insults and the violence of the prejudice" that she says she has endured.

Watching the proceedings, Rousseff’s mentor and predecessor as president, Luiz Inacio Lula da Silva, who is himself under investigation and will later this year stand trial for alleged obstruction of justice in the Petrobras probe, said his protegee "said what she had to say."

After Rousseff's speech, more than 50 senators from both the opposition and her bloc of supporters began questioning her. Her appearance is to be followed by a Senate vote on whether to remove her permanently from the presidency, expected as early as Tuesday, possibly going into Wednesday.

For Rousseff to be removed, at least 54 of the 81 senators must vote in favor. Counts by local media say at least 52 senators will vote for removal, while 18 are opposed and 11 have not said one way or another. In May, the same body voted 55-22 to impeach and suspend her.

As questioning of the suspended leader wore on, only a few senators were paying attention to Rousseff’s answers, which tended to be lengthy.

Rousseff's appearance came on the fourth day of a trial that has seen name-calling, shouting and a declaration by Senate President Renan Calheiros that "stupidity is limitless."

The process began late last year, with the Chamber of Deputies approving impeachment charges in April and the Senate in May.

The drama has consumed Brazil, with the proceedings continuing even during the Aug. 5-21 Olympic Games in Rio de Janeiro. On Monday, several hundred supporters demonstrated outside Congress, cheering when Rousseff arrived. A huge wall was erected to separate her supporters and pro-impeachment activists.

In Sao Paulo, another protest that was blocking one of the city’s main arteries was scattered by police using stun grenades.

Before Rousseff spoke, Supreme Court Chief Justice Ricardo Lewandowski, who is presiding over the trial, warned senators and spectators to remain silent.

When Rousseff finished her prepared remarks, many senators applauded, prompting Lewandowski to temporarily suspend the session.

"We are holding a judgment trial here, not a political debate," he said. (AP)