Brexit supporters’ closely held belief that Britain can leave the EU but still be “European” has run into a roadblock: the European Commission has ruled that UK cities will not be permitted to be named a European Capital of Culture in 2023.

The decision came after UK cities including Dundee, Nottingham, Leeds, Milton Keynes, and Belfast/Derry had submitted their official bids, and a week before the shortlist was announced. While the timing might be a bit harsh, the commission was indeed adhering to predetermined rules. While cities in non-EU countries have won the designation before—Istanbul, Reykjavik, and Stavanger among them—they came from countries that are either part of the European Economic Area, the European Free Trade Association, or applying to be members of the EU. By 2023, the UK will adhere to none of those criteria if it follows through with a “hard Brexit.”

While the grandstanding of British MPs on Twitter may further prove that Brexiteers live in a fantasyland where they can have their cake and eat it, the decision has a real-world downside. It’s a huge loss for UK cities hoping to boost tourism in a country where London attracts a hugely disproportionate share of visitors. According to VisitBritain, London accounts for 53% of all inbound visitor spending to the UK.

Indeed, when it comes to boosting tourism, the European Capital of Culture label is more than just semantics. Past cities that have served as the capital saw gains in visitors and local economic growth. Writing for the Huffington Post, Joe Anderson, the mayor of Liverpool—which served as the capital in 2008—explains how the city also experienced a much-needed boost in morale:

“Not only did it offer a stage to show the world the creative brilliance of our city, but it led to real, bottom-line benefits in terms of our visitor economy and improvements to our infrastructure… We saw 9.7 million visitors come to the city—an increase of a third—generating £754 million [$1 billion] for the local economy. Of the visitors surveyed 99% said they liked the general atmosphere and 97% felt welcome. Crucially, the research from academics at Liverpool University found that 85% of the city’s residents agreed that Liverpool was a better place to live in than before.”

For the past year and a half, the implications of Brexit have remained largely theoretical. Earlier this week, the EU announced that the headquarters of the European Medicines Agency and European Banking Authority will be moved from London to Amsterdam and Paris, respectively. In removing British cities from the running for European Capital of Culture as well, the reality of Britain’s divorce from the EU is beginning to dawn.