Critique the argument that applying tolls to reduce demand for existing roads is necessary due to limited space and capacity.
Sorry for the directness of this response, but this is stupidity.  Tory is not exactly a "leftist" politician.  In Metro Toronto we are unable to substantially increase the capacity of existing roads and we are unable to expand (widen) them to accommodate more cars.  There just isn't space.  So the only feasible way to reduce congestion is to reduce demand for the space there is; and in some cases like the DVP and Gardiner, this means applying the user pay principle:  tolls.