The amendments to the Canadian International Trade Tribunal Act provide the tribunal with authority to make such a determination on the request of domestic industry and then, specifically clause 51, the amendments to the customs tariff provide the Governor in Council with the authority to either suspend tariff concessions or reimpose the pre-FTA tariff levels as a result of a positive determination from the Canadian International Trade Tribunal.
On October 9th, 2014. See this statement in context.