The Danish EU Opt-Outs: Their Legal Significance, Past and Present

In June 1992, the Danes voted ‘no’ in a referendum on the approval of the new EU treaty that we know as ‘the Maastricht Treaty’. This meant that the foreseen ‘European Union’ could not be established unless a special solution was found to accommodate the Danish concerns regarding the new EU treaty. Such a solution was agreed in December 1992, and it includes the so-called Edinburgh-decision. The following year, Denmark held a new referendum with a positive outcome and the Maastricht Treaty was subsequently ratified. However, for the 30 years thereafter, Denmark would not participate in certain aspects of four specific areas of EU cooperation within Union Citizenship, the euro, defence cooperation and justice and police cooperation. This thesis forms the first comprehensive legal analysis of these so-called Danish EU opt-outs. It explains how they were designed in the Edinburgh Decision and how they later became integrated into the EU treaties. Moreover, it is explained what exactly the opt-outs mean and how they can be changed. That happened in June 2022, when the Danes voted to abolish the defence opt-out – whereas the other opt-outs are still in force. It may seem strange that legally it is possible for Denmark to enjoy a special position, however this thesis explains the reasons behind it. It then becomes clear why it is difficult to copy the Danish position, which indeed proved to be the case when the United Kingdom sought special arrangements before they ultimately decided to leave the EU altogether.