As a result of World War I and the Conscription Crisis of 1917, the party joined with pro-conscription Liberals to become the "Unionist Party", led by Robert Borden from 1917 to 1920, and then the "National Liberal and Conservative Party" until 1922. It then reverted to "Liberal-Conservative Party" until 1938, when it became simply the "National Conservative Party". It ran in the 1940 election as "National Government" even though it was in opposition.