[4] After the rejection of the Maastricht Treaty in the 1992 referendum, the Edinburgh Agreement was reached, which gave Denmark four opt-outs in the European Union (EU), one of which was on defence matters.

[3][8] The parties endorsed the agreement, which also included increased defence spending and the aim of ending the country's dependency on Russian gas.

[9] On 30 March, the Danish Foreign Ministry released two bills (draft laws) for organising the referendum and joining the Common Security and Defence Policy (CSDP).

[11] Following this, the wording of the referendum question, which did not mention the European Union nor the opt-out,[b] was criticised by the Danish People's Party and the Red-Green Alliance.

[12] Jeppe Kofod, Denmark's Foreign Minister, defended the wording, emphasising that the vote was about joining the other 26 EU member states.

"[13] Concern was raised that eliminating the opt-out and participating in the CSDP could eventually lead to Denmark having to join a European army if one were to be created in the future.

Foreign Minister Kofod committed that any such change would require treaty revisions, which would be put to the Danish people for approval in a new referendum.

European Commission President Ursula von der Leyen welcomed the result and said that Denmark and the EU "would benefit from the decision".