BRASILIA, Dec. 20 (Xinhua) -- Brazil's Federal Supreme Court on Friday authorized former President Jair Bolsonaro to undergo surgery, as President Luiz Inacio Lula da Silva vowed to veto a congressional bill that could reduce sentences for Bolsonaro and others convicted of an attempted coup.

Judge Alexandre de Moraes, overseeing Bolsonaro's case, ruled that the former president, currently serving a 27-year and three-month sentence for leading the 2022 attempted coup, may have the surgery recommended by a Federal Police medical board. The procedure is to treat a bilateral inguinal hernia and, while not an emergency, should be performed "as soon as possible" to prevent complications.

In the same decision, Moraes denied the request for house arrest presented by the former president's defense.

Lula reaffirmed on Friday that he would veto a congressional bill that revises certain sentencing calculations, which could reduce prison terms for Bolsonaro and other coup convicts.

"With all due respect to the deputies and senators who voted for the sentence reduction, I want to tell them that I will veto that law," Lula stated during an event in Sao Paolo.

Lula added, however, that if he issues a veto, Congress would still have the authority to override it in a subsequent vote -- a step that could benefit Bolsonaro. ■