Bolsonaro, a former army captain, was sentenced by the Supreme Court last September to 27 years in prison after being found guilty of conspiring to cling to power following his defeat by the current leftist president, Luiz Inacio Lula da Silva, in the 2022 election.

The president of the Superior Military Court (STM), Maria Elizabeth Rocha, said the tribunal will discuss a request from military prosecutors to declare Bolsonaro and four senior commanders to be unworthy of retaining their ranks and benefits in the armed forces.

Bolsonaro will be judged by a "court of honor" that will consider whether he retains his captain's rank despite being convicted over the coup plot, she said.

"The question is whether the crime for which he was convicted -- and whose sentence has already become final in the Supreme Federal Court -- allows him to keep the uniform or not," she said.

According to Rocha, the proceedings against the army generals -- Walter Braga Netto, Paulo Sergio Nogueira and Augusto Heleno -- and the former Navy commander, Admiral Almir Garnier Santos, are unprecedented in the South American country since the military court was established in 1808.

"This is the first time that we are truly...judging the loss of rank of a general officer."

Two STM judges will now conduct a preliminary assessment to determine whether to begin the trial before the full bench of 15 magistrates (10 military personnel and five civilians), for which no start date has been set.