A majority of Brazil's Supreme Court have rejected a last-ditch attempt by President Dilma Rousseff to halt an impeachment process against her in advance of a vote in Congress.
Justices denied a request on Thursday for an injunction against proceedings that Brazil's attorney general - the government lawyer - called "Kafkaesque" and said amounted to denying Rousseff the opportunity to defend herself.
Brazil's lower house of Congress is due to vote on Sunday on sending Rousseff to trial in the Senate.
The move could push Brazil from political paralysis into a chaotic power vacuum by ending the 13-year rule of Rousseff’s Workers' Party.
Earlier on Thursday, Jose Eduardo Cardozo, the attorney general, asked the top court for an injunction to suspend Sunday's lower house vote until the full court can rule on what he called procedural flaws in the impeachment process.
Reporting from Brazil's capital Brasilia, Al Jazeera's Latin America Editor Lucia Newman said: "The top court decided in a split vote. Two judges agreed with the attorney general that the president had been denied due process.
"Now nothing can stop the impeachment vote from taking place."
The lower house began debating the charges against the president on Friday morning.
"The debate will go on for at least 48 hours. The voting will start on Sunday afternoon. That's prime time in Brazil," Newman said.
Rousseff, already struggling with Brazil's worst economic crisis in decades and a historic corruption scandal, has lost support within her governing coalition.
She faces the growing likelihood of defeat in the lower house vote, which would send her impeachment to the Senate for trial on charges of breaking budget laws.
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If the Senate accepts her impeachment, Rousseff would be suspended and replaced by Vice President Michel Temer as soon as early May pending a trial that could last six months.
"The country's most popular entertainment show has been cancelled in order to broadcast the proceedings," Al Jazeera's Newsman said.
"By Sunday night, we should know whether or not the lower house has agreed to recommend the impeachment to the Senate, which will ultimately be in charge of the impeachment."
Rousseff, a former leftist guerrilla, had not been expected to resort to the Supreme Court until after Sunday's vote. Cardozo's request to the court was seen as a sign that her government now expects defeat.
|A majority of the judges denied on Thursday the government's request for an injunction against the impeachment proceedings [EPA]
Rousseff's opponents are just nine votes short of victory in the lower house, with 333 politicians backing impeachment, 124 opposed and 56 undecided or declining to respond, according to a survey by the Estado de S Paulo newspaper.
Several of the top court justices recently said that they did not think the court should interfere with the legislature's jurisdiction in the impeachment battle.
Brazil's largest political party, Rousseff's main coalition partner until it broke away two weeks ago, said most of its members in the lower house would back deposing her.
Leonardo Picciani, the lower chamber leader for the party, the Brazilian Democratic Movement Party, or PMDB, said 90 percent of the 68 members of his caucus would vote for impeachment.
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Source: Al Jazeera and agencies