British voters have gone to the polls to vote on a question that will have profound implications for the future of both their country and the rest of Europe: should Britain remain part of the European Union, or should it leave the EU and reclaim full sovereignty?
The vote has been dubbed "Brexit," and the stakes are high. The UK government has estimated that exiting the EU could cause the British economy to shrink by between 3.8 and 7.5 percent by 2030 — depending on how well subsequent negotiations for access to the European market ultimately went. Other reports have found smaller, but still significant, impacts.
Here’s what you need to know about the vote, including when polls close, what the polls show, and what happens next.
When will polls close, and when will we know the results?
Polls closed at 10pm British time. That was 5 pm Eastern Time in the US. But results aren’t expected for several hours after the polls close. Here’s a handy chart from MarketWatch showing how the night will go:
So if one side wins by a comfortable margin, Americans on the East Coast will likely find out before midnight. On the other hand, if the race is close, we may not get the results until well into the morning.
Who is expected to win the vote?
Polls suggested that the vote would be extremely close. An average of recent polls shows supporters of continued EU membership with 47 percent of the vote, compared to 45 percent for those wanting to leave the EU, with the rest undecided.
Earlier on Thursday, the betting markets were lopsided, showing a roughly 75 percent chance Britain will vote to stay in the EU. But once early results started to come in, they showed a bigger than expected vote for leaving. So now betting markets project a roughly 50/50 chance of a Leave vote.
Why do some Britons want to leave the EU?
The arguments for leaving the EU vary depending on which advocates you talk to. But the three most common arguments focus on the loss of UK sovereignty to the EU, the EU's burdensome economic regulations, and the EU's liberal rules for internal migration.
"The issue of sovereignty — of who governs you — is the most important question for any country," British journalist Douglas Murray told me in a recent interview. After two decades in which power has increasingly shifted toward the EU’s capital in Brussels, Murray wants to return full authority to the peoples' elected representatives in the British Parliament.
British conservatives also argue that EU regulations have become too burdensome, hampering the growth of the UK economy.
While arguments about political sovereignty and economic regulation dominate the intellectual case for Brexit, the political appeal of Brexit relies heavily on the emotionally charged issue of immigration.
EU law requires member states to admit an unlimited number of migrants from other EU countries. With much of Europe struggling economically, a lot of workers from less affluent EU states like Poland and Portugal have moved to the UK in search of work. There’s little Britain’s elected officials can do to stem these flows, and that rubs a lot of British voters the wrong way.
Fears about migration have been further stoked by the Syrian refugee crisis and recent terrorism incidents in Paris and elsewhere, with some Britons worrying that the EU’s free migration rules could make it easier for terrorists to enter the United Kingdom.
What’s the case for Britain staying in the EU?
British Prime Minister David Cameron, the head of the Conservative Party, is actually on the other side of the debate from most of his fellow conservatives, and is leading the campaign for Britain to stay in the EU. His argument, like that of most supporters of continued EU membership, is largely focused on economics.
Not only does the UK experience long-term economic benefits from being part of one of the world’s largest free-trade zones, advocates argue, the process of leaving the EU would itself be highly disruptive, leading to serious short-term economic pain.
"Remain" supporters warn that a vote to leave the EU could trigger an economic crisis, including a sharp fall in the value of the British pound and a stock market crash, and that a poorly managed British exit could lead to a recession.
In the longer run, Remain advocates say, a Brexit could threaten London’s status as Europe’s financial capital. Many overseas companies have established London headquarters to oversee their operations across Europe. But a British exit from the European Union could make it harder for goods and people to flow from the UK to the European continent, potentially causing companies to shift their workforces to other European capitals.
In addition, Cameron argues that EU membership makes Brits more secure by facilitating closer coordination among European law-enforcement organizations. He also argues that Britain’s EU membership amplifies the UK’s influence on the world stage, and that leaving the EU could cause Britain to become marginalized.
What will happen if Britain votes to leave the EU?
A Brexit vote is not legally binding, and there are a few ways that it could theoretically be blocked or overturned. However, as the BBC notes, "it would be seen as political suicide to go against the will of the people as expressed in a referendum."
Article 50 of the Treaty on European Union establishes the procedures for a member state to withdraw from the EU. It requires the member state to notify the EU of its withdrawal and obliges the EU to then try to negotiate a withdrawal agreement with that state.
A Brexit vote, however, does not represent that formal notification. That notification could take place within days — for example, when EU member countries meet for a summit that is scheduled for June 28 to 29. Or British officials might wait a few months to pull the trigger.
Once Britain invokes Article 50, it will have a two-year window in which to negotiate a new treaty to replace the terms of EU membership. Britain and EU leaders would have to hash out issues like trade tariffs, migration, and the regulation of everything from cars to agriculture.
In the best-case scenario, Britain may be able to negotiate access to the European market that isn’t that different from what they have now. Norway is not a member of the EU, but it has agreed to abide by a number of EU rules in exchange for favorable access to the European Common Market.
But there’s also a risk that EU and British leaders won’t see eye to eye. That’s a particularly serious concern because a Leave vote could cause David Cameron’s government to fall and be replaced by a more conservative leader. The EU may decide to strike a hard bargain to discourage other countries from leaving the EU. Or the UK’s new leader might not be willing to accept the kind of restrictions that come with a Norway-style deal.