The impeachment of Brazilian President Dilma Rousseff was thrown into confusion Monday when the speaker of the lower house of Congress annulled an April vote by lawmakers to launch the process.

Waldir Maranhao, the interim speaker of the lower house, wrote in an order seen by AFP that a new vote should take place on whether to impeach Rousseff.

The surprise move came just as the Senate was preparing to vote this week on whether to suspend Rousseff from office while an impeachment trial gets underway.