Pierre Karl Peladeau didn't reprise the dramatic fist-raising motion that accompanied his first political press conference, but the heir to the Quebecor media throne didn't step back from his message when he announced his candidacy for the Parti Quebecois leadership Thursday afternoon in Montreal. 

Asked what his main theme will be during the leadership campaign, the MNA for St. Jerome replied without hesitation: "Sovereignty."

"Sovereignty, yes," he said. "I think it's clear that I've committed to achieving Quebec sovereignty. It is my objective, my only objective."

While the new PQ leader will be chosen in May 2015, the next election is scheduled to be held in September 2018.

Peladeau said that, if elected leader, he will spend the next few years explaining what he considers the benefits of sovereignty to Quebecers.

When asked whether sovereignty could be negotiated with Ottawa, he replied: "I don't think the legitimacy of a nation, of a people, can be negotiated."

Polls have suggested the controlling shareholder of Quebecor Inc. (TSX:QBR.B) would be the front-runner in the race to succeed Pauline Marois as leader.

The man known in Quebec simply as PKP has been criticized in some quarters for refusing to sell his shares in Quebecor, whose extensive media holdings include the TVA television network, Le Journal de Montreal and the Videotron cable company.

He repeated on Thursday he would be willing to put his shares in a trust if he becomes PQ leader.

Peladeau joins caucus colleagues Jean-Francois Lisee, Bernard Drainville, Alexandre Cloutier and Martine Ouellet in the race. Another candidate is Pierre Cere, a spokesman for a group that defends the unemployed.

He will have to collect at least 2,000 signatures by next Jan. 30 as well as fork over a deposit of $20,000 to the party.

Premier Philippe Couillard said the fact Peladeau seems to have the inside track doesn't necessarily mean that much right now.

"Five or six months in politics is a long time," Couillard said in Dakar, Senegal, where he will attend this weekend's meeting of la Francophonie.

"There are several candidates and there will be debates with (PQ) members. But again, I have no intention of getting involved."

His opponents welcomed him to the race. "Bring it on," said Drainville of the celebrity candidate.

Ouellet pointed out that while Peladeau is well-known, he has committed many gaffes, most recently with regards to the relevance of the Bloc Quebecois.

She said Peladeau is obviously not a unifying member of the independence movement.

The rules for the PQ leadership race require all candidates collect 2,000 signatures from 50 ridings by Jan. 30, 2015, and give the PQ $20,000 as an entrance fee.

-With a file from The Canadian Press