To run, they will be required to put up $20,000 and have the signatures of at least 2,000 supporters.
Details of the leadership race were unveiled at a PQ meeting in Sherbrooke, Que., on Saturday.
Stephane Bedard has been interim PQ leader since shortly after the resignation of Pauline Marois following last April's provincial election.
While there are no official candidates so far, the front-runner is believed to be Pierre Karl Peladeau, the controlling shareholder of Quebecor Inc. (TSX:QBR.B).
The media magnate rejected a demand from potential leadership rival Jean-Francois Lisee on Saturday to sell his stake in Quebecor if he runs for the leadership.
"I have no intention of selling the shares that were bequeathed to me by father, who helped build Quebec as it is now," said Peladeau, who did not say whether he would re-evaluate his position if he becomes PQ leader in seven months.
Lisee said Peladeau would put the PQ in a position of "incredible vulnerability" vis-a-vis its political opponents if he kept his Quebecor stake.
The company is omnipresent in Quebec, with its properties including the TVA television network, Le Journal de Montreal, weekly newspapers and celebrity-driven magazines.