Britain has officially voted to leave the European Union in an historic referendum.
The Leave campaign is heading for an overall majority of 52% to 48%.
The result, predicted by ITV News at 4.35am, sent Westminster into disarray, plunged David Cameron's future into doubt and sent the pound tumbling to its lowest level since 1985.
The referendum turnout was 72.2%, with more than 30 million people voting - the highest since the 1992 general election.
ITV News Political Editor Robert Peston said the country should brace itself for the biggest "political and financial turmoil we have ever witnessed", while National Editor Allegra Stratton called Brexit a "ginormous" vote against the establishment.
Ukip leader Nigel Farage hailed the result, saying June 23 will "go down in history as our independence day".
He also called on David Cameron to resign "immediately", saying a "Brexit prime minister" was now needed.
Mr Cameron will address the country shortly.
Foreign Secretary Philip Hammond said voters have "spoken clearly" and the government's job is to "get on with that decision".
The Bank of England said it is "monitoring developments closely" and will "take all necessary steps to meet its responsibilities for monetary and financial stability".