Britain has voted to leave the European Union (EU) in its historic referendum. It was a 52% to 48% win for Brexit campaigners.

Sterling fell to decades-long lows against the US dollar as a Brexit grew likelier, having rallied initially as the last polls suggested a narrow lead for remain and kick-starting what is expected to be a highly volatile day on the financial markets.

The result was secured after a weaker showing for remain in what were expected to be some of its stronger areas, such as Liverpool and Scotland. Overall turnout was nearly 72% after around 30 million people turned up to vote.

Nigel Farage, leader of Ukip, who has long campaigned for Britain to leave the EU and whose political career was hanging in the balance, said that "dawn is breaking on an independent United Kingdom" as the likely result grew clearer.

Farage also said Prime Minister David Cameron, who campaigned for Remain, should "resign immediately". But two senior Conservatives at the fore of the official Leave campaign — Boris Johnson and Michael Gove — have signed a letter circulating among pro-leave Tory MPs calling on Cameron to stay as prime minister in the event of a Brexit. Cameron is yet to make a statement.

There is expected to be a volatile day on the markets in the aftermath of the decision as finance professionals and traders assess the implications. Negotiations on a formal Brexit as the country unpicks its complex relationship with the EU could take two years, creating a protracted period of political uncertainty. Some economists suggest the UK could tumble into recession as a result, with investors pulling money out of the country and others delaying decisions to pour more in.

The decision of the British public has gone against the appeals to remain from a significant number of the country's allies, major businesses and global institutions, including the US, Nato and IMF. Britain first joined the EU, then called the European Economic Community, in 1973, a decision endorsed in a referendum two years later.

But since then, critics have accused the EU of evolving beyond the trading bloc Britain signed up to and expanding into a political project that undermined the national sovereignty of its member states. The single most toxic issue is the EU's policy of the free movement of people, which has seen a large surge in migration to the UK as the bloc expanded to 28 members, incorporating poorer states in the central and east of Europe.

Some communities in Britain feel EU migrants have driven down the wages of workers and put enormous pressure on struggling public services, though pro-EU campaigners argue migration from the continent has boosted the economy, created jobs, and improved public finances because they pay more in than they take out.

Nigel Farage EU referendum
Nigel Farage, the leader of the United Kingdom Independence Party (UKIP) reacts at a party, as votes are counted for the EU referendum, in London, Britain June 24, 2016. REUTERS/Toby Melville