Vote leave posters are seen in a window in Chelsea, London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HQL9
A man arrives to vote at a polling station for the Referendum on the European Union in north London, Britain, June 23, 2016. REUTERS/Neil Hall - RTX2HQO8
A man leaves after voting at a polling station for the Referendum on the European Union in Biggin Hill, Britain, June 23, 2016. REUTERS/Dylan Martinez - RTX2HR4H
Ballot papers wait to be used at a polling station for the Referendum on the European Union in north London, Britain, June 23, 2016. REUTERS/Neil Hall - RTX2HTM7
Workers begin carry ballots after polling stations closed in the Referendum on the European Union in Glasgow, Scotland, Britain, June 23, 2016. REUTERS/Clodagh Kilcoyne TPX IMAGES OF THE DAY - RTX2HVC6
Nigel Farage, the leader of the United Kingdom Independence Party (UKIP), has a coffee in The Old Jail pub, after voting in the EU referendum, at a polling station in Biggin Hill, Britain June 23, 2016. REUTERS/Dylan Martinez
Supporters of the Stronger In Campaign react after heading the result from Orkney in the EU referendum at the Royal Festival Hall, in London, Britain June 24, 2016. REUTERS/Rob Stothard/Pool TPX IMAGES OF THE DAY - RTX2HW0O
Nigel Farage, the leader of the United Kingdom Independence Party (UKIP), reacts at a Leave.eu party after polling stations closed in the Referendum on the European Union in London, Britain, June 24, 2016. REUTERS/Toby Melville - RTX2HW97
A man wearing a European themed cycling jersey arrives to vote at a polling station for the Referendum on the European Union in north London, Britain, June 23, 2016. REUTERS/Neil Hall - RTX2HQH0
Nigel Farage, the leader of the United Kingdom Independence Party (UKIP), arrives to vote in the EU referendum, at a polling station in Biggin Hill, Britain June 23, 2016. REUTERS/Dylan Martinez - RTX2HQTB
Vote leave posters are seen in a window in Chelsea, London, Britain, June 23, 2016.. REUTERS/Toby Melville - RTX2HRD4
A sign is displayed opposite the M4 near Tata Steel works, on the day of the EU referendum, in Port Talbot in Wales, Britain June 23, 2016. REUTERS/Rebecca Naden - RTX2HUIR
Workers begin counting ballots after polling stations closed in the Referendum on the European Union in Glasgow, Scotland, Britain, June 23, 2016. REUTERS/Clodagh Kilcoyne - RTX2HVEF
Supporters of the Stronger In Campaign cheer as the EU referendum result from Gibraltar is announced at the Royal Festival Hall, in London, Britain June 23, 2016. REUTERS/Rob Stothard/Pool - RTX2HVKX
Supporters of the Stronger In Campaign react as results of the EU referendum are announced at the Royal Festival Hall, in London, Britain June 24, 2016. REUTERS/Rob Stothard/Pool - RTX2HW0Q
A traders from BGC Partners, a global brokerage company in London's Canary Wharf financial centre waits for European stock markets to open early June 24, 2016 after Britain voted to leave the European Union in the EU BREXIT referendum. REUTERS/Russell Boyce - RTX2HWW3
Scotland's First Minister Nicola Sturgeon leaves after voting in the EU referendum, at Broomhouse Community Hall in Glasgow, Scotland, Britain June 23, 2016. REUTERS/Clodagh Kilcoyne - RTX2HQEP
A man carries a painting outside a polling station for the Referendum on the European Union in north London, Britain, June 23, 2016. REUTERS/Stefan Wermuth - RTX2HQ1U
A man leaves after voting in the EU referendum, at a polling station in Biggin Hill, Britain June 23, 2016. REUTERS/Dylan Martinez - RTX2HQSG
A man cycles past a polling station in Chelsea in London, Britain June 23, 2016. REUTERS/Toby Melville - RTX2HR3L
Chelsea Pensioners leave after voting in the EU referendum, at a polling station in Chelsea in London, Britain June 23, 2016. REUTERS/Toby Melville - RTX2HR5P
A man looks at a notice outside a polling station in central London, Britain, June 23, 2016. REUTERS/Stefan Wermuth - RTX2HRJ8
A woman waits to use a mobile polling station in the village of Trecwn, Pembrokeshire in Wales, Britain June 23, 2016. REUTERS/Rebecca Naden - RTX2HRVK
Former London Mayor Boris Johnson and his wife Marina Wheeler arrive to vote in the EU referendum, at a polling station in north London, Britain June 23, 2016. REUTERS/Peter Nicholls TPX IMAGES OF THE DAY - RTX2HV3G
Workers begin counting ballots after polling stations closed in the Referendum on the European Union in Glasgow, Scotland, Britain, June 23, 2016. REUTERS/Clodagh Kilcoyne - RTX2HVCJ
Half-finished drinks and Union flags lie on a table at a A Leave.eu party after polling stations closed in the Referendum on the European Union in London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HVIO
A Leave.eu supporter wears a union flag paper hat after polling stations closed in the Referendum on the European Union in London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HVJJ
A union flag paper hat an champagne flutes are seen ona table at a Leave.eu party after polling stations closed in the Referendum on the European Union in London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HVPY
Leave supporters cheer results at a Leave.eu party after polling stations closed in the Referendum on the European Union in London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HVXU
People gathered in The Churchill Tavern, a British themed bar, react as the BBC predicts Briatin will leave the European Union, in the Manhattan borough of New York, U.S., June 23, 2016. REUTERS/Andrew Kelly - RTX2HWGU
A man lies on the ground in Parliament Square in London, Britain June 24, 2016. REUTERS/Toby Melville - RTX2HWQE
A woman photographs her daughter after she voted at a polling station for the Referendum on the European Union in north London, Britain, June 23, 2016. REUTERS/Neil Hall - RTX2HQI3
A policeman stands outside a polling station in Tower Hamlets in London, Britain June 23, 2016. REUTERS/Neil Hall - RTX2HQU8
People wait in line to cast their ballots during the EU referendum at a polling station in the British overseas territory of Gibraltar, historically claimed by Spain, June 23, 2016. REUTERS/Jon Nazca - RTX2HREK
A man walks past an illuminated EU referendum sign in Manchester Town Hall, Manchester, Britain June 23, 2016. REUTERS/Andrew Yates - RTX2HUXW
Nigel Farage, the leader of the United Kingdom Independence Party (UKIP), addresses supporters at a A Leave.eu party after polling stations closed in the Referendum on the European Union in London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HVI1
Leave.eu supporters celebrate the result in Sunderland after polling stations closed in the Referendum on the European Union in London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HVLU
Supporters of the Stronger In Campaign react as results of the EU referendum are announced at the Royal Festival Hall, in London, Britain June 24, 2016. REUTERS/Rob Stothard/Pool - RTX2HW59
A taxi driver holds a Union flag, as he celebrates following the result of the EU referendum, in central London, Britain June 24, 2016. REUTERS/Toby Melville - RTX2HX4G
Britain's Prime Minister David Cameron and his wife Samantha leave after voting in the EU referendum, at a polling station in central London, Britain June 23, 2016. REUTERS/Stefan Wermuth - RTX2HQAI
A woman cycles out of a polling station for the Referendum on the European Union in Chelsea, London, Britain, June 23, 2016. REUTERS/Toby Melville - RTX2HR30
A Vote Remain T-shirt hangs on a wall in the village of Penally, Near Tenby, Pembrokeshire in Wales, Britain June 23, 2016. REUTERS/Rebecca Naden - RTX2HRVZ
Workers begin counting ballots after polling stations closed in the Referendum on the European Union in Glasgow, Scotland, Britain, June 23, 2016. REUTERS/Clodagh Kilcoyne - RTX2HVCK
A workers counts ballots after polling stations closed in the Referendum on the European Union in Islington, London, Britain, June 23, 2016. REUTERS/Neil Hall - RTX2HVOB
Gibraltar's Chief Minister Fabian Picardo (L) and his wife Justine Olivero prepare their ballots before casting their votes for the EU referendum at a polling station in the British overseas territory of Gibraltar, historically claimed by Spain, June 23, 2016. REUTERS/Jon Nazca - RTX2HREL
Supporters of the Stronger In Campaign react as results of the EU referendum are announced at the Royal Festival Hall, in London, Britain June 24, 2016. REUTERS/Rob Stothard/Pool - RTX2HW0P
A Union flag flies in front of the moon in central London, Britain June 24, 2016. REUTERS/Toby Melville - RTX2HWVN
Britain's Brexit vote
Britons vote on whether to stay in the European Union.