Every opposition government ever opposes whatever large military procurement is proposed: It's easy to find negatives, and there is no real downside to be negative. Occasionally the rhetoric can get so over the top that it needs action (see the Liberals cancelling the EH-101, and then having to effective re-order it at a much higher price tag for less hardware), but generally it just quietly continues.

And the overwhelming reason Canada wants the F-35 has little to do with the aircraft, and everything to do with manufacturing partnership agreements that would see many billions of that order going to facilities in Canada, invigorating the aerospace industry.

Not saying it's a good purchase, because it isn't, but I wouldn't pin it on the Conservatives.