While some minor political parties have campaigned for English independence, all major UK-wide political parties adhere to the conventional view of British unionism, and oppose changing the constitutional status of England. Scottish demands for independence, rather than English demands, are seen as the most pressing threat to British unity; Scotland voted against independence at the referendum on 18 September 2014, but the topic is still being debated. The membership of Northern Ireland in the U.K. is an equally controversial topic.