Millions of Britons are heading to the polls to vote on whether the UK will remain a part of the European Union.
A record 46.5 million voters have signed up to weigh in on Thursday’s referendum that asks: “Should the United Kingdom remain a member of the European Union or leave the European Union?”
The divisive referendum has sparked the greatest emergency in the EU’s 60-year history.
The vote pits the Remain campaign, backed by British Prime Minister David Cameron and Labour Party leader Jeremy Corbon, against the Leave camp, led by the former London mayor, MP Boris Johnson.
Polling stations opened at 7am (06:00 GMT) and will close 10pm (21:00 GMT) local time.
There are no official exit polls because polling experts say the lack of recent comparable votes in Britain could make the results less reliable.Results from polling will, however, be released after the ballots close.
EU leaders have warned there will be no turning back from a vote to quite the 28-member bloc.
“Out is out,” European Commission chief Jean-Claude Juncker said in Brussels, dismissing any chances of a post-vote renegotiation of Britain’s EU membership terms.
French President Francois Hollande has said an exit by the UK would be “irreversible”.
The referendum has raised concerns across Europe that a British withdrawal could trigger a domino effect of exit votes and threaten the integrity of the bloc, already under severe strain from Eurozone and migration crises.
Tusk has previously said that a British leave vote could lead to the “destruction of not only the EU but also of Western political civilisation”.
The EU was created after the Second World War as an antidote to the nationalism which had devastated the continent. The movement for unity was led by France and Germany.