Quebec (AG) v Lacombe, 2010 SCC 38, [2010] 2 SCR 453, is a decision of the Supreme Court of Canada on the nature of the ancillary powers that arise from the doctrine of pith and substance in Canadian constitutional law.

The municipality applied for an injunction ordering the company to cease its aviation activities on Lac Gobeil on the ground that operation of the aerodrome and the associated business in that zone violated the by‑law.

The Superior Court of Quebec found that the legislation at issue was a valid municipal zoning by‑law, with only incidental effects on the federal subject of aeronautics.

The Quebec Court of Appeal set aside that decision, concluding that the by‑law, though valid, could not apply to the aerodrome because of the doctrine of interjurisdictional immunity.

A prohibition on aerodromes, even as part of a broad class of land uses, would result in an unacceptable narrowing of Parliament’s legislative options.