MONTREAL - Gilles Duceppe has issued a statement in which he insists he isn't trying to replace the leader of the Parti Quebecois, nor is he sitting on the sidelines waiting for her to fail.

The longtime federal politician says he hopes the PQ will rally around its leader in Quebec City.

Duceppe has written a formal letter to Pauline Marois, which he released publicly Tuesday.

In it, he expresses admiration for her and says he hopes she leads the party to triumph in the next provincial election.

"Nobody is better prepared than you. You have all the legitimacy, experience and determination to get there," he wrote to Marois.

"Over the last few months, you have shown exceptional courage, a key quality for someone who aspires to lead Quebec and carry it towards its full political liberty."

He also says he's not ready -- at least not yet -- to jump back into politics. He is rejecting, for now, an offer from Marois to get involved in the party.

"As I've told you in private, I'm not ruling out joining you and the Parti Quebecois in the future, but I don't feel ready right now to jump back into political life," he wrote.

"That does not in any way mean, as some are suggesting, that I am waiting 'at the reserve of the republic.' I have no designs on anyone's job.

"I do not encourage or support any challenge to your leadership."

Duceppe was the longtime leader of the Bloc Quebecois and had a string of political successes, until the party was suddenly decimated in the May 2 federal election.

But polls suggest he remains far more popular than Marois and might be the PQ's best hope of performing well in the election expected next year.

There is grumbling within PQ ranks that Marois should leave, given a string of disastrous polls. One MNA speculated openly that Duceppe was the party's "ace in the pocket" -- and could replace Marois within six months.

But Duceppe's letter appeared designed to distance himself from any such revolt.

"Through this letter, I am reiterating a message addressed to all sovereigntists: let's let Pauline Marois and the Parti Quebecois do their job. Let's stop dividing ourselves," he wrote.