England’s biggest festival is happening on the same day as the country’s most important referendum in a generation. Tomorrow Brits will make a historic vote on whether or not to remain in the European Union. Here’s the thing — Glastonbury starts today (the day before the vote) and there’s concern that the 200,000 attendees won’t be able to vote unless they already voted by mail. Organizers said they will be unable to offer polling places on site at the festival. Glastonbury co-organizer Emily Eavis is one of many in the music industry to strongly advocate for the “remain” position and called the referendum “without question, one of the most important votes we’ll ever have to cast,” telling attendees about the importance of voting by mail. Festival organizers also emailed all confirmed ticket-holders in April with information on early voting, and its Twitter feed has repeatedly instructed its 611,000 followers on how to cast postal or proxy ballots.