Tory Leader Olive Crane is threatening to withdraw from the CBC debate if the province's three other registered parties are not included.
Sheryl MacAulay, a spokeswoman for Crane, said the leader's position won't change.
"She stands firm in her commitment that she will not participate in the debate unless all five leaders are there," MacAulay said Friday.
CBC spokesman Jeff Keay said the network has not changed its position on who can participate, adding that they hope Crane will reconsider her position — or there may not be a debate at all.
Representatives of the New Democrats, Green Party and Island Party of P.E.I. have all been demanding the public broadcaster include them in the Sept. 21 event.
Keay said the leaders of all five parties will be involved in a debate on CBC Radio next week.
He said the decision was made to exclude the NDP, Greens and Island party because the Tories and Liberals are the only parties represented in the legislature and the only ones that have a "reasonable chance" of forming the next government.
As well, Keay said all of the parties will get plenty of media coverage during the campaign.
"Throughout the election campaign all of the positions of the parties are going to be reported upon as part of the election coverage," he said in an interview. "That's what we always do."
The leader of the P.E.I. New Democrats, James Rodd, issued a statement saying he is considering seeking legal advice.
"It's bad enough that the Liberals and Conservatives in Prince Edward Island have the advantage of $800,000 a year in campaign funds provided by the corporate sector," Rodd said. "But now a public body is giving the two old-line parties another leg up by excluding the leaders of the other officially registered parties."
Rodd said the CBC's main reason for excluding three parties isn't sound.
"CBC managers ... do not have a magic ball that tells them the outcome of elections," he said. "Rather than claiming to know what voters are likely to do, CBC managers should demonstrate the kind of independent and objective distance that is supposed to be applied in the field of journalism."
The provincial election is scheduled for Oct. 3.
At dissolution, there were 24 Liberals, two Conservatives and one seat was vacant in the legislature.