Britain votes on EU membership after tight and bitter campaign

 London : Britons were voting on Thursday on whether to stay in the European Union in a referendum that has split the nation and is being nervously watched by financial markets and politicians across the world.

Opinion polls taken before the vote indicated the outcome is too close to forecast, although two polls published late on Wednesday suggested a swing towards "Remain".

Much will depend on turnout, with younger Britons seen as more supportive of the EU than their elders but less likely to vote.

Polling stations opened at 0600 GMT (0200 EDT) and will close at 2100, with results expected to be announced by the 382 individual local counting areas between around 0100 and 0300 on Friday.

Prime Minister David Cameron called the vote under pressure from the anti-EU wing of his Conservative Party and the surging UK Independence Party (UKIP), hoping to end decades of debate over Britain's ties with Europe.

The "Leave" campaign says Britain's economy would benefit from an exit from the EU, or Brexit. Cameron says it would cause financial chaos and impoverish the nation.

He voted early, and said on Twitter: "Vote Remain - so that our children and grandchildren have a brighter future."

His main rival, former London mayor Boris Johnson, whose decision to support "Leave" galvanized its campaign, told voters on Wednesday this was the "last chance to sort this out".

It is only the third referendum in British history. The first, also about membership of what was then called the European Economic Community, was in 1975.

Most polls put the "Leave" and "Remain" camps neck-and-neck at the end of a bitter four-month campaign that was dominated by immigration and the economy, and shaken by the murder of pro-EU lawmaker Jo Cox last week.