(CNN) A Brazilian lawmaker's surprise announcement Monday sent the country's scandal-plagued government spinning as a key question looms: Will a Senate vote to impeach President Dilma Rousseff go forward as expected this week?

So far, there are more questions than answers.

The confusion began Monday when Waldir Maranhao, acting speaker of Brazil's lower house, said he wanted to annul last month's vote by the legislative body approving a motion to impeach Rousseff.

That vote was the first major legislative step in the impeachment process, paving the way for another vote that was expected to occur this week. Senators were slated to vote Wednesday on whether Rousseff should face an impeachment trial.

But it's not clear what impact the acting speaker's announcement will have on the high-profile case, which has cast a harsh spotlight on Brazil's government just months before the country is set to host the Olympics

The president of the Brazilian Senate, Renan Calheiros, subsequently told his chamber that he didn't "recognize" the motion from the lower house annulling the impeachment vote, and was going to go ahead with the Senate schedule. The vote to impeach Rousseff is planned for Wednesday.

Shortly after he made his announcement Calheiros was forced to suspend the Senate session briefly due to shouting and arguing.

Legal experts: Decision could be overturned

Legal experts told CNN and CNN affiliate TV Record that the annulment of the lower house vote could be overturned by Brazil's Supreme Court. Lawmakers could also challenge it themselves and demand that it be put to a vote immediately in the lower house, the experts said.

But what will happen next is anyone's guess.

"This is completely unprecedented," said Gustavo Binenbojm, a constitutional lawyer. "But the tendency is to knock it down. Any legislator can challenge it in the plenary. The Supreme Court could issue an injunction. There are a lot of ways to suspend it."

The Order of Attorneys of Brazil said it was "extremely concerned" and would take the appropriate legal steps to fight "the absurd and unacceptable decision."

As for whether Maranhao's announcement has much chance of sticking, experts said it was unlikely, given that the vote to impeach Rousseff passed the lower house overwhelmingly last month.

Photos: Protests in impeachment battle against President Dilma Rousseff Brazilian lawmakers shouted, scuffled and even sang as they debated whether to impeach President Dilma Rousseff on Sunday. Over a period of six hours they eventually voted 367-137 to impeach the president. Hide Caption 1 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff Deputies of the Lower House of Congress exchange words during the vote. After the success of the motion to impeach, it will be considered by the parliament's upper house. Hide Caption 2 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff A total of 367 lawmakers in the lower house voted to impeach Rousseff, the country's first female president, by more than the two-thirds majority required by law. Hide Caption 3 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff The impeachment motion will next go to the country's Senate. If a majority approves it, Rousseff will have to step down for 180 days to defend herself in an impeachment trial. Hide Caption 4 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff Pro-impeachment supporters watch a live television broadcast as Lower House Speaker Eduardo Cunha, himself under corruption investigation, speaks as deputies prepare to cast their votes in the impeachment process. Hide Caption 5 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff As lawmakers spoke their minds on the floor of Congress, throngs of demonstrators waited for word of the results. Hide Caption 6 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff Protesters opposed to the impeachment react as they watch the voting session on television in Sao Paulo, Brazil. Hide Caption 7 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff A pro-impeachment supporter kisses a Brazilian flag while watching a live television broadcast moments after lower house deputies vote to approve the motion to continue the impeachment process. Hide Caption 8 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff Brazilian flags hang from apartments during demonstrations on the day of voting. Hide Caption 9 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff Pro-impeachment supporters celebrate after politicians vote to approve the motion to impeach Rousseff. The motion will now be brought before the Senate, the Brazilian congress' upper house. Hide Caption 10 of 11 Photos: Protests in impeachment battle against President Dilma Rousseff Protesters in Sao Paolo, opposed to the impeachment, watch the voting session on television en masse. Hide Caption 11 of 11

At least one Senate official said Monday that the announcement wouldn't affect the Senate's impeachment proceedings.

Maranhao became speaker of the house last week after the Supreme Court suspended the previous speaker for allegedly obstructing corruption investigations and intimidating lawmakers.

Rousseff could be suspended for six months

Rousseff is accused of breaking budgetary laws by borrowing from state banks to cover a shortfall in the country's deficit and pay for social programs.

If Senators approve a motion for an impeachment trial against her, she'll be required to leave the presidency for 180 days and defend herself. Brazilian Vice President Michel Temer would temporarily take the reins.

Rousseff has publicly defended her record on numerous occasions, describing the impeachment process as a coup and arguing that other Brazilian leaders have used the same accounting approach.

"I will fight to survive, not just for my term in office," Rousseff told CNN's Christiane Amanpour last month , "but I will fight, because what I am advocating and defending is the democratic principle that governs political life in Brazil."

When Rousseff became Brazil's first woman president in 2010, she had high approval ratings. She is very unpopular now, predominantly because Brazil is suffering through a recession and a bribery scandal involving state-run oil company Petrobras and dozens of politicians in her party and governing coalition. Rousseff is not implicated in the scandal, but millions of Brazilians are demanding she be removed.