Aquino, only son of the country's revered democracy icon, Cory Aquino, has an insurmountable lead of more than 5 million votes over his nearest rival, former President Joseph Estrada, based on unofficial tallies from the election commission.

The deadline for Congress to declare the winners in the presidential and vice-presidential elections is June 30.

"It's safe to say that we'll be able to proclaim by Monday," Juan Miguel Zubiri, Senate majority floor leader and a close ally of outgoing President Gloria Macapagal Arroyo, told reporters.

By Tuesday, lawmakers had confirmed 203 vote tallies out of a total of 278 from provinces, cities, embassies and consulates.

The canvass showed Aquino had 9.6 million votes, or 42.5 percent of more than 22.5 million votes counted, and Estrada had 5.9 million or 26.3 percent. The election commission has estimated around 38 million people voted on May 10.

Zubiri said 50 to 60 tallies could be canvassed on Wednesday, with the main risk of delay coming from Congress's move to seek an explanation of the failure of about a dozen provinces and cities outside Manila to electronically transmit vote results.

"I can't make promises, but our best effort is to complete our job by Thursday evening and proclaim winners next week," said Zubiri.

"We're not trying to railroad the process. We've deferred tallies from provinces and cities which submitted incomplete documents, or those with discrepancies. But, we'll tabulate them as soon as election officials give us valid explanations."

In the vice presidential race, Jejomar Binay, Estrada's running mate and long-time mayor of Manila's financial district, leads Manuel Roxas, Aquino's running mate, by less than 300,000 votes.

The election commission's unofficial tally showed, with more than 90 percent of votes counted, Binay led Roxas by about 800,000 votes.

Roxas' lawyers have claimed he was cheated because up to 2.6 million votes were nullified due to ambiguous marks on ballots.

Binay's lawyers said that should not delay the proclamation of vice-president, and said Roxas could file an election protest before the Supreme Court.

The Congress will devote Friday's sitting to pending bills, including a Freedom of Information Act to promote transparency in government deals, before its term ends on June 30.