Polls opened early today in a historic referendum to decide whether the UK will stay in or leave the 28-nation European Union even as the result remained too close to call with opinion polls showing a very tight race that could go either way.
Both sides of the campaign have urged the nearly 46,499,537 registered voters, including 1.2 million British Indians, for a big turnout as Prime Minister David Cameron made his final appeal to "get out there and vote Remain" and reject the "untruths" of the camp in favour of 'Brexit' or Britain's exit from the EU.
Cameron will vote in his constituency of Witney, Oxfordshire, before returning to Downing Street to watch the results come in.
"It is a fact that our economy will be weaker if we leave and stronger if we stay," Cameron told supporters in Birmingham yesterday as he travelled up and down the country to make his final push for votes.
Immigration to Britain, which has risen significantly in recent years, is a key issue in the referendum that has seriously divided the country.
On the opposing side, former London mayor Boris Johnson, who is widely touted as a future prime minister, headed the final drive for the Vote Leave campaign, insisted his side was "on the verge of victory" and that today could mark the UK's "independence day".
The last poll tracker of the Daily Telegraph shows "Remain" at 51 per cent and "Leave" at 49 per cent, reflecting the neck-and-neck nature of the campaign throughout a four-month period since Cameron announced the date of the referendum in February.
The referendum ballot paper asks a 'Yes' or 'No' question: "Should the United Kingdom remain a member of the European Union or leave the European Union?" and whichever side gets more than half of all votes cast is considered to have won.
The weather forecast for polling day remains mixed, with thunderstorms causing flooding in some parts of the country.
A low turnout is likely to benefit the "Leave" side, however the general expectation is of a bigger turnout than the 2015 general election which was around 66 per cent.
After the referendum polls close at 10 pm local time, sealed ballot boxes will be collected and transported to the count venue for each of the 382 local counting areas.
These represent all 380 local government areas in England, Scotland and Wales, plus one each for Northern Ireland and Gibraltar.
Individual areas' results will then be declared throughout
the night, along with results from 11 regional counts.
The UK's Electoral Commission estimates a final result around breakfast time tomorrow.
In a departure from the norm, no major broadcasters have commissioned any exit polls over concerns about accuracy following the fiasco of the last general elections, when a hung Parliament had been predicted wrongly instead of a big Conservative party majority.
The resultwillbe declared by Jenny Watson, the chair of the UK's Electoral Commission and thereferendum's chief counting officer, at Manchester Town Hall on Friday morning.
The European Union is made up of 28 countries who have come together for trade and security.
It was originally set up as the European Economic Community (EEC) in 1958 with six members: Belgium, Germany, France, Italy, Luxembourg and the Netherlands. The EEC changed its name to the European Union (EU) in 1993. The UK had joined the EEC back in 1973.
There has only been one other UK-wide referendum on the issue of EU membership, in 1975 when the country voted to stay in the European Community.
Eligible voters in today's referendum include anyone over the age of 18 who is a British citizen resident in the UK and UK nationals who have lived abroad for less than 15 years.
Citizens of Ireland, Malta and Cyprus resident in the UK can vote as can Commonwealth citizens resident in the UK and Gibraltar, including Indians.
