David Cameron set the date for a British referendum on membership in the European Union for June 23 of this year. He promises to run a vigorous campaign to stay in, whereas many high ranking officials, including the Mayor of London, Boris Johnson, and Justice Secretary, Michael Gove, promise to lead a strong initiative to abandon the Union.

Britain’s membership in the European Union has been a subject of debate since the 1970s, with opinions fluctuating every decade or so. As of late, the UKIP party led by Nigel Farage has bolstered anti-EU sentiments with a one-plank platform of British independence. In 2011, UKIP made a few strides with the European Union Act, requiring any EU treaty that gives Brussels substantive new powers to be subject to a British referendum.

Many believe that if Britain leaves, the EU will be unable to live up to its full potential—the EU needs Britain more than Britain needs the EU. This is a plausible scenario. But there is a more likely second scenario in which Britain leaving the EU tanks exports and negotiating power.

Some arguments for leaving the EU include a new power to negotiate independent trade treaties with India, China, and the United States. Proponents contend that, if not restricted by harsh EU regulations, British exports would grow dramatically.

If Britain does pass the referendum and leaves the EU, it still needs the EU to take the majority of its exports. Like Norway and Switzerland, Britain would still need free movement from EU countries and would have to send a large payment to the EU for trade benefits.

A number of Brits want to leave the EU to claim back some sovereignty lost to European judges interfering with business practices and labor laws. But the potential gain in sovereignty would be minor.

Britain already gives up sovereignty and decision-making power to throw its weight around in NATO, the IMF, and other power-sharing institutions. In abandoning the EU, Britain would be pushed to the outside of negotiations but would still be affected by EU decisions.

Immigration would be an exception. Almost half of British immigrants come from the EU, and with open borders there is nothing Britain can do to stop the influx. Free from the EU, Britain could regulate its own immigration policy, but it would come at a high cost.

Long-term effects of Brexit would spread beyond immigration and economics. If Britain leaves the EU, Scotland would have greater reason to break up the United Kingdom. Results from the Scottish referendum in September 2014 show that a Brexit may be the force to push the last 6 percent to vote for Scottish independence. Leaving the EU could spell economic catastrophe for Britain and Scotland if they decide to divorce.

European Union officials know that Britain holds an important place in a bloc of countries struggling with immigration and economic crises. The EU would suffer if Britain left—EU policy would turn increasingly conservative and self-serving if left to other current powers, Germany for one.

The EU is steadily becoming more important in implementing of international security measures, and a Brexit would steal the majority of EU military might. This would not only weaken the security of the EU but also burden poorer countries with military responsibilities abroad for which they are not equipped. It is not surprising that Vladimir Putin supports a British exit whereas President Obama stands in opposition.

The British referendum may seem to promise sovereignty and independence to Britain, but hopefully UKIP proponents and their supporters can see before June how a Brexit will hurt Britain and the European Union.