This is indeed something historic…
Who & Why – from BBC:-
Who wanted the UK to leave the EU?
The UK Independence Party, which won the last European elections, and received nearly four million votes – 13% of those cast – in May’s general election, campaigned for Britain’s exit from the EU.
About half of Conservative MPs, including five cabinet ministers, several Labour MPs and the DUP were also in favour of leaving.
What were their reasons for wanting the UK to leave?
They said Britain was being held back by the EU, which they said imposed too many rules on business and charged billions of pounds a year in membership fees for little in return. They also wanted Britain to take back full control of its borders and reduce the number of people coming here to live and/or work.
One of the main principles of EU membership is “free movement”, which means you don’t need to get a visa to go and live in another EU country. The Leave campaign also objected to the idea of “ever closer union” and what they see as moves towards the creation of a “United States of Europe”.
Who wanted the UK to stay in the EU?
Prime Minister David Cameron wanted Britain to stay in the EU. Sixteen members of his cabinet also backed staying in. The Conservative Party pledged to be neutral in the campaign – but the Labour Party, SNP, Plaid Cymru and the Lib Dems were all in favour of staying in.
US president Barack Obama also wanted Britain to remain in the EU, as did other EU nations such as France and Germany.
What were their reasons for wanting the UK to stay?
Those campaigning for Britain to stay in the EU said it gets a big boost from membership – it makes selling things to other EU countries easier and, they argued, the flow of immigrants, most of whom are young and keen to work, fuels economic growth and helps pay for public services.
They also said Britain’s status in the world would be damaged by leaving and that we are more secure as part of the 28 nation club, rather than going it alone.