Free trade means the elimination of protective tariffs on goods traded between two or more countries. Free trade with the US has been a constant debate in Canadian economic policy since the days of Macdonald's protectionist National Policy. Traditionally, the Liberals have been staunch free traders. 
The most recent Free Trade debate occurred during the 1988 election campaign. Brian Mulroney's Conservatives argued that the removal of tariffs would create jobs and preserve living standards.  John Turner and free trade opponents argued that Canadians would lose thousands of jobs, control over the pricing of resources, and even control over social programs and cultural industries.
PM Mulroney and President Reagan signed the Free Trade Agreement in January 1988.