John Tory said Wednesday he will release a plan to pay for a new north-south subway line during his campaign for mayor.

TTC officials have said a subway line to take pressure off the overloaded Yonge-University-Spadina line (known as the downtown relief line or DRL) is a priority, but so far there's no plan to pay for it. Tory said during his mayoralty campaign he will outline a plan to deliver the line and pay for it.

"Before this campaign is over ... I will put forward a complete and I believe totally defensible plan that will spell out how I am going to pay for it," he said. "And the citizens of Toronto will be able to judge that when I put it out."

Tory also said he would not re-open the debate over transit expansion in Scarborough. After a protracted back-and-forth fight, council opted to expand the subway line along that route, instead of a much cheaper light rail plan

Tory made the comments on Metro Morning Wednesday, part of the show's week-long series of candidate interviews. Olivia Chow appeared Monday and David Soknacki was on the show Tuesday.

Coun. Karen Stintz will appear tomorrow and Mayor Rob Ford will be on the show Friday.

Tory, who lost the 2003 mayor's race to David Miller, also said he could not endorse Porter Airlines' plan to expand Billy Bishop airport, saying there are too many unanswered questions in the proposal as it stands now.

"I'm skeptical about the expansion plans," Tory told host Matt Galloway.

"Right now, based on the information that is available and the lack of answers to those 45 questions, I would not go ahead with this."

Tory pointed to his record in top boardroom jobs and political experience as the former provincial PC leader as reasons why he would make a good mayor. He also said Mayor Rob Ford, who is running for re-election in the Oct. 27 vote, has failed at the job due largely to his personal problems.

"[Ford] has lost that ability to work with the council and other governments," said Tory. "You just can't get things done on big projects without being able to work with other people."