QUEBEC CITY — Outgoing Quebec premier Jean Charest introduced Jean-Marc Fournier as interim Liberal leader Wednesday, and the new party boss immediately issued a warning to the separatist Parti Quebecois.

Fournier, who will be justice minister until next week, told a news conference he would work with premier-elect Pauline Marois on issues such as job creation.

But he also warned the minority Parti Quebecois government that the Liberals will stand for a united Canada.

"We'll be there...to oppose them if they ever want to try some (measures) bringing us to some scheme of separation," said Fournier, a veteran lawyer and longtime Liberal MNA.

"We're going to work immediately to regain the trust of the population," Fournier added as Charest and 50 newly elected Liberal MNAs stood behind him.

Last week, voters tossed the Liberals from power after nine years, ending Charest's 28-year political career.

The PQ won a 54-seat minority in the 125-seat legislature.

Marois didn't mention separation at all in her first news conference as premier-elect the day after the election.

But she has promised to request a meeting with Prime Minister Stephen Harper to demand the federal government repatriate several powers to Quebec in areas of language, culture and employment insurance.

It still isn't clear if she'll be able to make good on a pledge to extend French-language laws to small businesses and federal agencies in Quebec.

She has also said she'll bar francophones and immigrants from attending English community colleges.

Such hardline language measures would require amendments to Bill 101, which couldn't pass without support from the Liberals or the centre-right CAQ party, which has 19 seats.

Neither opposition party has said if it would support Marois' language proposals.