Legislators are gearing up to revive Brazil's stalled impeachment process as early as this week after millions of people on Sunday demanded the ouster of President Dilma Rousseff.

Lower house speaker Eduardo Cunha said he would call for the creation of a congressional committee tasked with issuing a recommendation on impeachment the day after the Supreme Court issues new guidelines on the process. The top court is expected to make its decision Wednesday.

"I'll move the process along quickly once the rules are clarified," Cunha wrote in a text, adding that he could even call a meeting for Friday. That would be an unusual move in a parliament that's usually only in session from Tuesday through Thursday.

Support for Rousseff began crumbling in Congress in recent weeks after fresh allegations drew her Workers' Party deeper into a two-year corruption scandal over kickbacks at state-run oil company Petrobras. Nationwide protests on Sunday, the largest on record, are likely to prompt more legislators to reconsider their support for Rousseff, potentially speeding up her ouster, said political analyst Ricardo Ribeiro.

"After months of diddle-daddling, we're reaching a make-or-break point for Dilma," said Ribeiro, who works at MCM business consulting firm in Sao Paulo. "And more and more legislators are thinking she won't make it."

The massive turnout for Sunday's protests "suggests that her fall may come more quickly than we were anticipating," Eurasia Group political risk consulting firm wrote. Eurasia analysts Christopher Garman, Joao Augusto de Castro Neves and Cameron Combs now say Rousseff probably will be impeached by May.

Rousseff

Military police estimate at least 3.6 million people demonstrated on Sunday, while event organizers put the number at 6.9 million. Polling firm Datafolha said the demonstrations in Sao Paulo exceeded those for general elections before the fall of Brazil's 21-year military dictatorship in 1985.

Still, there are no guarantees that the lower house won't get bogged down like it did after Cunha opened the process in early December.