Two out of five Supreme Court justices tasked with deciding the fate of the former Brazilian president, Jair Bolsonaro, have found the ex-leader guilty of plotting a coup.
But Bolsonaro will only be convicted if at least one more justice finds him guilty. The former president has denied all the charges against him.
The first justice to cast his vote, Alexandre de Moraes, said there was no doubt that there had been a coup attempt after Bolsonaro lost the 2022 presidential election to his left-wing rival, Luiz Inácio Lula da Silva.
The second justice, Flávio Dino, also found Bolsonaro guilty of all five charges against him. The trial will continue on Wednesday.
When the session starts at 09:00 local (12:00GMT), all eyes will be on Justice Luiz Fux, whose turn it will be to cast his vote.
If he also finds Bolsonaro guilty on all the charges, the simple majority needed to convict the former president will have been reached.
If convicted, Bolsonaro - who governed Brazil from January 2019 to December 2022 - could face a lengthy sentence of more than 40 years in prison.
So far, the statements by the two justices who have cast their votes have been damning for the former president.
Justice Moraes said that Bolsonaro had led the criminal organisation which he alleged was behind the attempted coup.
Bolsonaro's lawyer, Celso Vilardi, said he did not agree with the two justices' views but stressed he would always respect the decision of the Supreme Court.
The former president and his seven co-defendants in the trial - some of whom are top military officers - stand accused of trying to prevent President-elect Lula from taking up office.
According to investigators, the defendants failed to enlist enough support from the military for the plan to go ahead.
However, Moraes argued that the defendants' efforts culminated in the storming of Congress, the Supreme Court, and the presidential palace by thousands of Bolsonaro supporters on 8 January 2023 - one week after Lula was sworn into office.
But, according to Moraes, Brazil had come close to descending into authoritarianism: We are slowly forgetting that Brazil almost returned to its 20-year dictatorship because a criminal organisation, comprised of a political group, doesn't know how to lose elections.
There is no doubt that the defendant, Jair Bolsonaro, held meetings with Armed Forces commanders to discuss the breach of constitutional norms, Moraes said.
The ex-president was not in court when Justices Moraes and Dino announced their guilty votes, with his lawyers stating he was suffering from health problems.
The trial has deepened divisions in Brazil, with supporters of Bolsonaro alleging that the five-member panel tasked with the case is biased.
Critics argue that Brazil's institutions need to act decisively when under threat, reminding citizens of the country's tumultuous history with military rule.
