Scottish unionism is politically opposed to Scottish independence, which would mean Scotland leaving the UK and becoming an independent state. Political parties which support Scottish independence include: the Scottish National Party (SNP) and the Scottish Greens. The SNP have formed the devolved Scottish Government since 2007. After the SNP won an overall majority in the 2011 Scottish Parliament election, the UK and Scottish governments agreed to hold a referendum on Scottish independence, which was held on 18 September 2014. The three main UK political parties formed the Better Together campaign, supporting Scotland remaining part of the UK. The referendum resulted in a victory for the "No" (unionist) campaign, with 55.3% of votes cast for "No" to Scottish independence, and 44.7% cast for "Yes" to Scottish independence.