The acting leader of Brazil's lower house annulled an earlier vote on the president's impeachment, citing procedural flaws, according to a Monday report from Reuters. That vote took place April 17.
The news throws expectations for the week into disarray. On Wednesday, Brazil's Senate is scheduled to vote on whether to proceed with Rousseff's impeachment; a simple majority vote yes was to mean that Rousseff would immediately step down and a trial would kick off shortly.
Impeachment may be irreversible at this point, however, even after the reversal in the lower house. Edwin Gutierrez, head of emerging market sovereign debt at Aberdeen Asset Management, said his firm is "unfazed" by Monday's news, which he called a "mere stall tactic" that could be reversed by Brazil's Supreme Court.
"Even if somehow they manage to re-vote in the house, they can stage that vote as many times as they want and the result will be the same every time," he said. "It's not like impeachment passed by one vote."
A total of 367 lower-house lawmakers voted for impeachment last month, versus 137 against, surpassing the two-thirds majority required .
Eurasia Group said in a note early Monday afternoon that the annulment of the vote is "unlikely to hold."