Turnout: 72.00%
About this election
On 3 December 2015 Denmark held a referendum on whether to convert its sweeping opt-out from EU justice and home affairs into a flexible "opt-in" model, under which Denmark could choose, case by case, to participate in individual EU measures. Voters rejected the proposal by 53.11% to 46.89%, choosing to keep the full opt-out — a result widely read as a defeat for the political establishment and a reflection of deep Euroscepticism among Danish voters.
Denmark's justice opt-out dates from the 1993 Edinburgh Agreement, negotiated after Danish voters initially rejected the Maastricht Treaty. By 2015, the opt-out threatened Denmark's continued membership of Europol, the EU police agency, which was moving to a new legal basis. To preserve cooperation on cross-border crime, a broad majority of parties — the governing Venstre, the Social Democrats, the Social Liberals, the Conservatives and the Socialist People's Party — backed converting the blanket opt-out into a case-by-case opt-in. The Danish People's Party, the Red–Green Alliance and the Liberal Alliance campaigned for "No".
Supporters argued that an opt-in was essential to stay in Europol and to keep Denmark engaged in European police and judicial cooperation without surrendering sovereignty over asylum and immigration. Opponents warned that an opt-in would hand Brussels a foot in the door on sensitive areas, particularly asylum policy, and tap into broader distrust of the EU. The migration crisis then dominating European politics sharpened those fears and is widely thought to have hardened the "No" vote.
On a turnout of 72.00% — very high for a Danish referendum — 53.11% voted No and 46.89% Yes. The "No" camp won across most of the country; only the Capital Region (Hovedstaden) produced a narrow "Yes" majority, while rural and provincial areas voted No more heavily. The map above shows the Yes share by region.
The result meant Denmark retained its full justice opt-out and therefore had to leave Europol as a full member. The government subsequently negotiated a special parallel agreement giving Denmark associated, operational access to Europol — a workaround that preserved practical cooperation but confirmed Denmark's place at the margins of EU justice integration. The vote was a political embarrassment for the pro-European mainstream and demonstrated, once again, the limits of Danish voters' appetite for deeper EU integration.
Official results from Statistics Denmark (Danmarks Statistik) — dst.dk/valg. The map shows the Yes share by region.
Compiled and reviewed by Bartłomiej Paruzel, Election Data Analyst, from official results. See our data methodology.