The party caucus gathered twice Wednesday, including a three-hour meeting that wrapped up after 11 p.m. ET, to discuss her leadership.
That followed a report in Montreal's La Presse newspaper that said all but a handful of elected members hoped to see Marois leave before the next election.
Marois emerged from the meeting late Wednesday to say she is staying on and will lead the PQ in the next election.
"I won't leave," Marois told reporters after the emergency caucus meeting.
"I'm here to stay and I'll be there for the next election. And that was made very clear to the caucus."
It's unclear whether Marois' resolve to stick around is — and will continue to be — backed by her party.
There is considerable nervousness within the ranks that despite Premier Jean Charest's massive unpopularity and string of scandals, his poll numbers are surprisingly still better than the PQ's.
Some members fear the near-annihilation of the Bloc Quebecois in last spring's federal election could happen at the provincial level to a party that has shaped the history of Quebec since its founding in 1968.
From outside the room, applause for Marois could be overheard. But even she conceded the feelings in the room were not unanimous.
"I have very good support from the caucus,'' she said. "People made certain comments, but that's normal."
The PQ has forced nearly all of its leaders out the door. Even the party's founding icon, Rene Levesque, was not immune to internal rebellion.
Since then, similar troubles have bedevilled Pierre Marc Johnson, Lucien Bouchard, Bernard Landry and Andre Boisclair. Only Jacques Parizeau, beloved by the party grassroots for his hardline push for Quebec independence, quit without any pressure from the rank-and-file.
Marois is now facing that pressure. Most members who walked past reporters into an earlier Wednesday meeting said little when asked about her.
One who did express support for Marois did so in less than glowing terms. Claude Pinard compared the party to an alcoholic — and said it has hit the bottom of the barrel with nowhere to go but up.
"There's a climate of nervousness,'' Pinard said before the evening meeting.
Marois has been steadily criticized by factions within the party over her leadership style and go-slow approach to sovereignty.
Several members of the caucus have bolted in recent months, including heavyweights Louise Beaudoin, Pierre Curzi and Lisette Lapointe, the wife of ex-premier Parizeau.
Marois, who joined the cabinet under Levesque and held several key posts including health and finance in subsequent PQ administrations, has vowed she won't be pushed out of the job.
She received a sterling score of 93 per cent in a leadership review earlier this year.
When she subsequently lost several defectors during the party's last round of internal turmoil this spring Marois demanded, and received, a statement of support from her remaining caucus members.
She was acclaimed PQ leader in 2007 after two previous, unsuccessful tries.
She took over the party from Boisclair who led the PQ to its worst electoral performance in a generation — and third-party status — in the 2007 provincial election.
She was able to return it to Opposition status in the 2008 provincial election, where she was lauded for a solid performance.
Marois has since spent most of this term pummelling Charest with questions on a variety of scandals related to corruption and cronyism.
But her poll numbers remain dismal.
In fact, the parties both in government and in Opposition remain far behind a virtual foe _ a movement led by ex-PQ minister Francois Legault that is expected to become an official party within weeks.
Legault's party will likely endorse left-of-centre social policies and right-of-centre fiscal reforms.