The party says the debate organizers made the decision to pick a date that "only worked for some parties, not all."
The tersely worded statement says the party had hoped there would have been an equal opportunity for all parties to talk about their plans for the region.
It says it was led to believe that there was a desire for a "comprehensive discussion."
NDP Leader Andrea Horwath and Liberal Leader Kathleen Wynne have said they'll participate in the debate in Thunder Bay, Ont.
Hudak and Horwath held a northern debate in the 2011 election, but then-premier Dalton McGuinty declined, citing a scheduling conflict.