Brazil's Supreme Court on Friday rejected a last-ditch attempt by President Dilma Rousseff to halt the impeachment process against her, clearing the way for a key vote in Congress.
If the vote passes on Sunday, the Senate will have authority to open a trial against Rousseff, who is accused of illegal government accounting tricks to boost her re-election chances.
If the Senate finds her guilty with another two-thirds vote, she would be forced from office.
Rousseff, who has vowed to go down fighting, also tried another tack by repeating an offer to forge a political compromise with opponents if deputies throw out impeachment on Sunday.