The 2016 Brexit referendum was a public vote held in the United Kingdom on June 23, 2016, to decide whether the UK should remain a member of the European Union or leave. Approximately 33.5 million people voted, with 51.9% choosing to leave and 48.1% opting to stay. The referendum's outcome led to significant political and economic changes in the UK, including the resignation of then-Prime Minister David Cameron. The decision to leave the EU initiated a complex negotiation process regarding the terms of the UK's exit, commonly referred to as "Brexit."