Brazil’s Supreme Court justices were on the verge of rejecting former leftist president Luiz Inacio Lula da Silva’s plea to avoid prison while he appeals a corruption conviction, in a vote that would likely end his political career and deepen divisions in the country.

A pivotal vote was cast late Wednesday by Justice Rosa Weber against Lula’s request to avoid jail and begin serving his 12-year sentence for accepting bribes. Weber was seen as a swing vote, and her decision likely means a majority will rule the same way.