Parliamentary opposition is a form of political opposition to a designated government, particularly in a Westminster-based parliamentary system. This article uses the term government as it is used in Parliamentary systems, i.e. meaning the administration or the cabinet rather than the state. In some countries, the title of "Official Opposition" is conferred upon the largest political party sitting in opposition in the legislature, with said party's leader being accorded the title "Leader of the Opposition".
In first-past-the-post assemblies, where the tendency to gravitate into two major parties or party groupings operates strongly, government and opposition roles can go to the two main groupings serially in alternation.
