What is 'Brexit'?

It's the issue of whether Britain should exit the European Union or not — a question that will be decided in a historic referendum on June 23. Polls show Brits split almost evenly between the "Remain" and "Leave'' camps, with more than 10 percent undecided.
Britain's most influential lawmakers and business leaders have broken into two warring sides, with Prime Minister David Cameron, who wants Britain to remain in the EU, facing a stinging rebellion within his own Conservative Party.

When did Britain join the EU?

In 1973, though not without much hand-wringing beforehand. As an island that's always had a literal and psychic separation from the rest of Europe, Britain has been a largely unenthusiastic member of the EU. In fact, it has maintained a semidetached relationship, refusing to sign on to the single Euro currency or the Schengen Agreement on passport-free travel throughout the Continent. 

What are the pros of a Brexit?

Economically, Britain would immediately save $12 billion a year in EU budget payments. Freed from famously cumbersome EU regulations, Brexit supporters say, Britain would attract greater investment and become a more dynamic economic hub — particularly if it still had full access to the EU's tariff-free single market. But that's a big if, and would rely on Britain renegotiating a new trade deal with the EU's remaining 27 member states — many of whom, post-Brexit, would want to make a bitter example of the U.K., to discourage other members from fleeing.

What about immigration?

This is one of the biggest issues for Euroskeptics. Since it didn't embrace fully open borders with Europe, Britain can already demand that visitors present a passport when entering the country. But under the EU's labor rules, any citizen of a member state has the right to live and work in another member state — a rule that has allowed some 942,000 Eastern Europeans to move to the U.K. as the EU has expanded its borders. Brexiters say these migrants have overwhelmed the housing system and abused Britain's generous in-work benefits. At least 34,000 of them are getting child benefits for children who do not even live in the U.K. and sending that money — totaling about $42 million a year — back to their home countries. Leaving the EU would allow Britain more control over how many migrants are allowed to enter. That's become a big selling point after the influx of 1 million refugees into EU countries.

What would happen if Britain left?

A "Leave" vote would trigger Article 50 of the Lisbon Treaty, starting a step-by-step, two-year withdrawal process. Britain's Parliament would have to repeal all the laws that bind the country to the EU and come up with new trading and travel agreements with the remaining 27 nations.

What about the wider consequences?

There could be many. Scotland, which sends half of its international exports to the EU, strongly favors the Remain side, and has threatened to hold a snap referendum enabling it to break away from the U.K. if there is a Brexit. Without a seat at the EU table, Britain might find itself more isolated and its already diminished status as a world power weakened. The EU would lose its second-largest financial contributor, and might find itself crumbling at the edges — particularly if other member states decide to follow Britain's lead. But given that no country has ever left the EU, it's impossible to say with any confidence what might happen.