Liberal Leader Stephane Dion is expected to announce his resignation Monday afternoon at a press conference in Ottawa.
His office released a media alert on Friday announcing Monday's 2 p.m. press conference.
Dion has not spoken publicly since losing his bid to become prime minister in Tuesday's election.
CTV's Ottawa Bureau Chief Robert Fife reported Friday evening that Dion was leaning towards stepping down.
"I've spoken to people very close to Mr. Dion and they say they expect him to step down on Monday," Fife said. "He's a defeated general without an army and he knows he can't survive a leadership review vote."
Fife said that party elders have said that Liberal MP Ken Dryden may take over an interim leader as the Liberals prepare for a leadership convention.
Former Liberal Party president Stephen LeDrew was one of many Liberals, on and off the record, who have called for Dion to step down.
"What he should do is resign immediately," LeDrew told CTV's Mike Duffy Live Friday. "I think this man is intellectually arrogant.
"When Dion said on election night, 'I've been elected opposition minister' -- that was the goofiest statement in political history.
"Stephane Dion does not pay attention to the party or pay attention to advice."
The Toronto Star's Linda Diebel wrote a book about Dion and covered his campaign this year. She says that Dion has taken his election loss quite hard.
"He's in a lot of pain, and he's making a decision," Diebel told Mike Duffy Live Friday.
Insiders say that until election night Dion thought he had a shot at becoming prime minister, despite poor polling numbers.
"That was very much the impression I had," Diebel said regarding the issue.
Calls for action
On Thursday, Liberal spokesperson George Young said media reports that Dion would announce his resignation this week were false.
"We will properly advise the media when M. Dion is prepared to speak publicly," Young said.
Meanwhile, on Thursday night, Liberal MP Joe Volpe publicly called on Dion to "signal his intentions" about whether he will step down.
"I think the best thing that would happen for the party, and indeed for Mr. Dion, would be if he gives a signal as early as possible," Joe Volpe told CTV's Mike Duffy Live Thursday.
Volpe pointed out that the Liberals have an impending convention in May 2009 and Dion needs to let the party know if that conference is going to become a leadership convention.
When asked if Dion should quit, Volpe responded that "Dion has earned the right to stay on probably as an interim leader."
If Dion doesn't resign, he'll automatically face a vote of confidence at the convention -- which few predict he could survive.
The Liberals campaigned on an unpopular carbon tax and ended up winning only 76 seats, their poorest showing since 1984. Before the election was called, the Liberals held 95 seats in Parliament.