Brazil faces one of the most dramatic weeks in its recent history with senators expected to suspend President Dilma Rousseff and open an impeachment trial against her.
The political crisis comes on top of one of the deepest recessions in decades in Latin America's biggest economy, just three months before it hosts the Olympic Games in Rio from August 5 to 21.
Senators gather on Wednesday to discuss whether to launch impeachment hearings against Rousseff over allegations that she covered up shortfalls in the public accounts while running for reelection.
Around 50 of the 81 senators have said they will vote in favor of an impeachment trial, well over the simple majority needed to launch the process. The vote is expected on Thursday.
Rousseff will then be suspended for six months while the trial in the Senate runs its course, before a definitive vote on whether to remove her from office for good.
The affair has heightened tensions in the country which has been shaken by a separate corruption scandal involving state oil company Petrobras that has implicated numerous politicians including allies and enemies of Rousseff.
Ministers are reportedly clearing their desks in government offices in the capital Brasilia, where the legislature is currently suspended pending the impeachment proceedings.
Rousseff, 68, has branded the drive to get rid of her a "coup" by "traitors" such as Vice President Michel Temer, 75, who will take over as head of state if she is suspended.
"This is an indirect election disguised as impeachment. The usurpers of power, who unfortunately include the vice president, are complicit in an extremely serious procedure," she said on Friday.
In further declarations on Saturday, she called for full elections.
"If they want to pass political judgment on my government, they should turn to the Brazilian people, not to impeachment."
Temer is the center-right former coalition partner of Rousseff, herself a leftist former guerrilla member who was tortured under Brazil's dictatorship in the 1970s.
He has begun preparing an interim government, planning tough emergency economic measures such as budget cuts and pensions and labor reforms.
Recent polls indicated that about 60 percent of Brazilians want Rousseff to leave office. But they also showed a similar proportion reject Temer and prefer fresh elections.
Rousseff has not been formally accused of corruption like many of her rivals. But prosecutors have called for her to be investigated for allegedly trying to obstruct a probe into the Petrobras scandal.
Among the high-profile suspects in that affair is her presidential predecessor Luiz Inacio Lula da Silva.
Another is one of her chief rivals, congressional speaker Eduardo Cunha, who was suspended by the Supreme Court on Thursday over the scandal.
A deputy from Rousseff's Workers' Party appealed to the Supreme Court to block the impeachment, saying Cunha and congressional leaders illegally pressured lower house deputies to approve the proceedings. The court was not expected to overturn the lower house's decision to pass the case to the Senate.
Temer's name has been mentioned in the Petrobras affair but he has not been formally investigated by the courts. However, a Sao Paulo court has fined him for campaign financing irregularities.