The claim of middle power is pretty uncontroversial. We're at the level above places like Spain and below places like Italy but in both of their company. It means we contribute around the world and have some political, economic, and military clout.
There are a lot of 'uncontroversial claims' made by the Canadian media/political/academic opinion makers which don't stand up very well to scrutiny. The truth is we contribute very little around the world, and have virtually no clout or influence.