Fears triggered by last week’s terrorist attacks in Brussels by the Islamic State hang heavily over the prospects for Britain’s decision on whether or not to stay within the European Union. British Prime Minister David Cameron has called for a referendum on June 23 to decide on a “Brexit,” or a British exit from the EU.

The Brussels attacks, combined with concerns over the influx of migrants into the EU from the Middle East and North Africa, have provided more ammunition to right-wing political parties in the United Kingdom that are pro-Brexit. Recent polls put a Brexit closer to becoming a reality than it seemed a few months ago.

However, a Brexit will disrupt trade and hurt businesses both in the U.K. and the EU at a time when Europe needs investments and jobs, according to Wharton experts.

The Brussels attacks will certainly affect sentiment in favor of Brexit, noted Mauro Guillén , Wharton management professor and director of the school’s Lauder Institute . “There are people and parties in the U.K.…