The free trade agreement was concluded in 1988 and NAFTA extended most of the provisions of the free trade agreement to Mexico. NAFTA was negotiated by the governments of U.S. President George H.W. Bush, Canadian Prime Minister Brian Mulroney and Mexican Prime Minister Carlos Salinas de Gortari. An interim agreement on the pact was reached in August 1992 and signed by the three heads of state and government on 17 December. NAFTA was ratified by the national parliaments of the three countries in 1993 and came into force on January 1, 1994. The implementation legislation was delayed in the Senate, which had a majority of the Liberal Party. In part in response to these delays, Mulroney declared an election in 1988. The trade agreement was by far the most important theme of the campaign, leading some to call it “free trade”. It was the first Canadian election to make major third-party election advertisements, where supporters and opponents used lobbyists to buy television advertising. The Liberal Party of Canada had traditionally supported free trade.
 Free trade in natural products was a central theme in the 1911 Canadian Legislative Elections. The Conservative Party campaigned with anti-American rhetoric, and the Liberals lost the election. The issue of free trade has not returned to this level of national importance in Canada for many decades. The phenomenon of “cross-border shopping,” in which Canadians would take day trips to U.S. border towns to use duty-free goods and a high Canadian dollar, caused a mini-boom for these cities. The loss of many Canadian jobs, particularly in Ontario`s manufacturing industry during the recession of the early 1990s, was attributed (fairly or not) to the free trade agreement. The second parallel agreement is the North American Environmental Cooperation Agreement (NAAEC), which established the Commission for Environmental Cooperation (CEC) in 1994. The CEC is responsible for strengthening regional cooperation in the environmental field, reducing potential trade and environmental conflicts and promoting effective enforcement of environmental legislation. It also facilitates public cooperation and participation in efforts to promote conservation, protection and improvement of the North American environment.