Factbox: Brazil's presidential impeachment process

Brazil's President Dilma Rousseff smiles as she attends a meeting with jurists at Planalto Palace in Brasilia, Brazil, March 22, 2016. REUTERS/Adriano Machado

BRASILIA (Reuters) - Brazil’s largest party said on Tuesday it was leaving President Dilma Rousseff’s governing coalition and pulling its members from her government, striking a blow at her efforts to fight impeachment proceedings in Congress.

Here are the next steps in the presidential impeachment under Brazil’s Constitution:

1) A 65-member committee of the Chamber of Deputies, or lower house, must decide if the impeachment bid is valid. Speaker Eduardo Cunha, a fierce critic of Rousseff, has said he will speed up the process as much as possible. The full lower house must then vote on the committee’s decision and balloting could take place as soon as mid-April.

Rousseff’s opponents need the votes of two-thirds of 513 congressmen. Cunha does not vote. Rousseff requires 171 votes or abstentions to block impeachment.

2) If Rousseff loses the lower house vote, the Senate must then vote on whether to go ahead with putting her on trial. The timing is unclear, with Senate Speaker Renan Calheiros saying the Supreme Court has to provide a calendar for how the process should unfold. Many observers expect the vote to take place in early May.

If the Senate votes by a simple majority to accept the case, Rousseff is suspended at the start of the trial and Vice President Michel Temer becomes acting president.

The Senate has 180 days to conduct its trial, chaired by the president of the Supreme Court. Analysts say impeachment, if it goes ahead, will be a quick process given Brazil’s political crisis and could be decided by the end of May.

3) If two-thirds of the 81-seat Senate, or 54 senators, vote for impeachment, Rousseff is stripped of her political rights and cannot run for elected office for eight years. Temer will be confirmed as president for the rest of Rousseff’s term, ending on Dec. 31, 2018.

Reporting by Daniel Flynn in Sao Paulo; Editing by Peter Cooney