Brazilian president Dilma Rouseff called the impeachment move against her as a coup against a democratically elected president. REUTERS

Brazilian president Dilma Rousseff faces impeachment charges for alleged manipulation of the budget after a congressional committee voted on Monday to put the president on trial.

This will now be tested in the lower house on April 17 or 18. In the lower house, 342 votes are needed to send the matter on to the Senate for a final decision. Opinion polls suggest 292 are in favour, 115 against and 106 undecided.

In the senate a simple majority is enough to decide the president's fate. Even as the senate decides her fate, Rouseff faces immediate suspension for six months and vice president Michel Temer will be made acting president.

The 68-year-old president belonging to the Workers' Party has denied the charges and called the move a coup against a democratically elected president. Rousseff's chief of staff Jaques Wagner said government will continue working to muster enough votes to block impeachment in the lower house. But experts believe the vote in the committee will have a snowballing effect.

Around the same time an audio message from Temer to his party was accidentally released on social media and made its way to the website of a newspaper.

"We need a government of national salvation and national unity," Temer said in the audio, claiming he was merely showing preparedness to lead while not wanting to go ahead of events. "We need to unite all the political parties, and all the parties should be ready to collaborate to drag Brazil out of this crisis."

The president recently lost support of key coalition allies in Congress, including her main partner, vice president Temer's PMDB party, reports Reuters.

Rousseff's aides are confident that the president faces "lesser charges" of manipulating the budget to conceal a deficit as compared to many in the opposition and senate whose names have been linked with large-scale bribes and corruption around state-run oil company Petrobas. The president's popularity has been on the wane since her second term which has seen unemployment rates soar and the economy weaken in the worst recession in decades. Millions took to the street in support of the impeachment move.

The country is to play host to Olympic Games in less than a 100 days.