A referendum on the abolition of the defence opt-out, one of the country's opt-outs from the European Union, was held in Denmark on 1 June 2022. The referendum was announced on 6 March 2022 following a broad multi-party defence agreement reached during the 2022 Russian invasion of Ukraine. The referendum question was answered positively with the "Yes" side securing just over two-thirds of the vote.

Background After the rejection of the Maastricht Treaty in the 1992 referendum, the Edinburgh Agreement was reached, granting Denmark four opt-outs from European Union (EU) policies, including one on defence matters. This compromise allowed Denmark to ratify the Maastricht Treaty in 1993. The defence opt-out meant that Denmark did not participate in the Common Security and Defence Policy or EU military operations. In addition, the opt-out excluded Denmark from decision-making processes in the EU related to military operations.

The Russian invasion of Ukraine in February 2022 sent shockwaves across Europe, prompting countries to reassess their security and defense strategies. In response, the Danish government, under Prime Minister Mette Frederiksen, reconsidered Denmark’s longstanding opt-out from EU defense cooperation. The government and EU officials viewed Denmark's potential alignment with EU defense policies as essential for strengthening Europe’s security framework. Less than two weeks after Russia's invasion, Frederiksen called for a referendum to abolish the defense opt-out, marking what was seen as a decisive shift in Denmark's defense policy.

This was the third referendum held on Denmark's EU opt-outs. In 2000, the Danish electorate rejected the adoption of the euro as national currency, and in 2015, a proposal to modify the justice opt-out was also rejected.

For a referendum to be rejected, a majority of participating voters must vote against it, and those voting against must constitute at least 30% of the total electorate. However, the parties supporting the defence agreement agreed that the result would be respected regardless of voter turnout.

Campaign

The defence agreement was signed and presented by the leaders of the Social Democrats, Venstre, Socialist People's Party, Social Liberal Party, and the Conservative People's Party. The parties supporting the agreement also backed measures to increase defence spending and reduce Denmark's reliance on Russian gas. The Liberal Alliance and the Christian Democrats also endorsed the "Yes" option, while the Independent Greens voted in favor but did not issued a recommendation to voters. Opposing the abolition of the opt-out, the Danish People's Party, New Right, Young Conservatives and the Red–Green Alliance endorsed the vote "No". PositionPolitical partiesYesSocial DemocratsVenstreGreen LeftLiberal AllianceConservativesSocial LiberalsChristian DemocratsNoRed–Green AllianceNew RightDanish People's PartyNeutralIndependent Greens 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). Following this, the wording of the referendum question, which did not mention the European Union nor the opt-out, was criticised by the Danish People's Party and the Red-Green Alliance. Jeppe Kofod, Denmark's Foreign Minister, defended the original wording, emphasising that the vote was about aligning Denmark with the other 26 EU member states. However, following the criticism, Kofod announced a revised wording on 7 April, which read: "Do you vote for or against Denmark's participation in the European defence and security co-operation by abolishing the EU defence opt-out?"

There were concerns that eliminating the opt-out and participating in the CSDP could eventually lead to Denmark having to join a future European army if one were created. Foreign Minister Kofod committed that any such change would require treaty revisions, which would require approval by the Danish people in a new referendum.

Television debates Four major television debates involving the leaders of parties represented in the Folketing were held.

Date Organisers Venue Yes NoAVFBCIQÅKMØOD 11 MayDR1 War Museum, Copenhagen P P P P P P P P P P P P P 18 MayTV 2 News Dokk1, Aarhus S P PNININININININI P PNI 29 MayTV2Christiansborg, Copenhagen P P P P P P P P P P P P P 31 May DR1 DR Koncerthuset, Copenhagen P P P P P P P P P P P P P

Opinion polls Date(s)Polling agencySampleLead30 May 2022Epinion44%28%19%16%27–30 May 2022Voxmeter1,09153%28%19%25%2327 May 2022Voxmeter2,00851%27%22%24%1622 May 2022Voxmeter45.5%30%24.6%15.5%9 May 2022Epinion38%27%35%11%6 May 2022Megafon1,00939%26%35%13%20–27 April 2022Epinion2,09039%26%35%13%18–24 April 2022Voxmeter39.5%32.1%28.4%7.4%4–10 April 2022Voxmeter/Ritzau38.8%32.4%28.8%6.4%31 March – 7 April 2022Epinion2,10236%27%37%9%28 March – 3 April 2022Voxmeter/Ritzau1,00739.2%35.8%25%3.4%22–28 March 2022Voxmeter1,00040.3%35.4%24.3%4.9%14–20 March 2022Voxmeter1,50938.2%30.9%30.9%7.3%6–20 March 2022Wilke1,00042%30%28%12%8–15 March 2022Epinion1,02038%23%39%15%7–11 March 2022Voxmeter1,50944.2%28.7%27.1%15.5%7–8 March 2022Megafon2,05455%23%22%32%6 March: The government of Prime Minister Mette Frederiksen announces a referendum on the Danish defence opt-out to be held on 1 June.3–4 March 2022Megafon1,09249%27%23%22%

Results The result meant that 43.38% of the registered electorate had voted for the proposal, and 21.49% had voted against.

By constituency DistrictForAgainstValidBlankInvalidTotalVotes%Votes%Capital Region of Denmark 581,703 69.5% 254,874 30.5% 836,577 10,007 1,775848,359Copenhagen 235,847 69.4% 104,221 30.6% 340,068 5,108 827346,0031. Østerbro 27,096 74.1% 9,467 25.9% 36,563 510 8237,1552. Sundbyvester 21,591 69.7% 9,395 30.3% 30,986 428 9031,5043. Indre By 19,612 74.5% 6,710 25.5% 26,322 365 8126,7684. Sundbyøster 17,135 67.9% 8,100 32.1% 25,235 357 6225,6545. Nørrebro 22,004 65.3% 11,672 34.7% 33,676 715 8734,4786. Bispebjerg 12,065 60.5% 7,885 39.5% 19,950 400 6020,4107. Brønshøj 22,649 67.2% 11,053 32.8% 33,702 498 8234,2828. Valby 16,844 67.8% 7,987 32.2% 24,831 352 7425,2579. Vesterbro 22,042 69.6% 9,614 30.4% 31,656 570 7832,30410. Falkoner 20,180 76.7% 6,126 23.3% 26,306 344 3926,68911. Slots 17,313 72.1% 6,684 27.9% 23,997 327 5224,37612. Tårnby 17,316 64.5% 9,528 35.5% 26,844 242 4027,126Greater Copenhagen 160,842 68.1% 75,490 31.9% 236,342 2,407 508239,2571. Gentofte 29,382 80.2% 7,268 19.8% 36,650 287 6637,0032. Lyngby 22,099 77.6% 6,378 22.4% 28,477 296 5328,8263. Gladsaxe 20,642 69.1% 9,244 30.9% 29,886 344 5230,2824. Rødovre 18,978 64.4% 10,506 35.6% 29,484 343 6029,8875. Hvidovre 14,015 62.9% 8,260 37.1% 22,275 242 2422,5416. Brøndby 16,091 60.0% 10,738 40.0% 26,829 233 8127,1437. Taastrup 18,831 61.8% 11,625 38.2% 30,456 292 7430,8228. Ballerup 20,814 64.5% 11,471 35.5% 32,285 370 9832,753North Zealand 172,177 71.8% 67,611 28.2% 239,788 2,176 396242,3601. Helsingør 21,396 69.3% 9,488 30.7% 30,884 290 6431,2382. Fredensborg 25,446 75.8% 8,121 24.2% 33,567 247 2933,8433. Hillerød 32,921 68.2% 15,334 31.8% 48,255 470 6148,7864. Frederikssund 24,668 63.4% 14,262 36.6% 38,930 404 9139,4255. Egedal 32,324 73.7% 11,547 26.3% 43,871 407 6344,3416. Rudersdal 35,422 80.0% 8,859 20.0% 44,281 358 8844,727Bornholm 12,827 62.9% 7,552 37.1% 20,379 316 4420,7391. Rønne 6,390 63.3% 3,699 36.7% 10,089 167 2110,2772. Aakirkeby 6,437 62.6% 3,853 37.4% 10,290 149 2310,462Region Zealand & Region of Southern Denmark 646,102 64.6% 354,611 35.4% 1,000,713 11,340 2,1831,014,236Zealand 265,947 64.0% 149,567 36.0% 415,514 4,428 837420,7791. Lolland 11,245 59.2% 7,758 40.8% 19,003 220 6319,2862. Guldborgsund 18,635 61.3% 11,747 38.7% 30,382 357 8230,8213. Vordingborg 14,973 62.8% 8,879 37.2% 23,852 270 3824,1604. Næstved 25,668 62.5% 15,394 37.5% 41,062 423 7441,5595. Faxe 18,740 61.7% 11,640 38.3% 30,380 287 8930,7566. Køge 29,952 66.6% 15,042 33.4% 44,994 537 7245,6037. Greve 23,601 67.7% 11,240 32.3% 34,841 283 5535,1798. Roskilde 32,809 72.0% 12,767 28.0% 45,576 521 7946,1769. Holbæk 22,771 64.2% 12,704 35.8% 35,475 380 7635,93110. Kalundborg 24,685 60.0% 16,460 40.0% 41,145 423 9141,65911. Ringsted 20,232 64.0% 11,385 36.0% 31,617 387 5932,06312. Slagelse 22,636 60.9% 14,551 39.1% 37,187 340 5937,586Funen 165,365 67.3% 80,211 32.7% 245,576 3,166 576249,3181. Odense Øst 20,137 66.6% 10,084 33.4% 30,221 473 9630,7902. Odense Vest 19,795 68.4% 9,162 31.6% 28,957 381 7129,4093. Odense Syd 25,484 72.6% 9,600 27.4% 35,084 483 8335,6504. Assens 13,840 66.0% 7,131 34.0% 20,971 237 5721,2655. Middelfart 23,544 66.0% 12,125 34.0% 35,669 396 9336,1586. Nyborg 18,800 65.8% 9,778 34.2% 28,578 365 4828,9917. Svendborg 23,954 65.4% 12,656 34.6% 36,610 473 7837,1618. Faaborg 19,811 67.2% 9,675 32.8% 29,486 358 5029,894South Jutland 214,790 63.2% 124,833 36.8% 339,623 3,746 770344,1391. Sønderborg 22,352 63.5% 12,853 36.5% 35,205 379 9335,6772. Aabenraa 16,458 61.3% 10,410 38.7% 26,868 277 5627,2013. Tønder 10,295 60.6% 6,700 39.4% 16,995 217 4217,2544. Esbjerg By 16,859 59.1% 11,686 40.9% 28,545 289 6028,8945. Esbjerg Omegn 16,651 63.8% 9,432 36.2% 26,083 258 4426,3856. Varde 14,852 63.1% 8,698 36.9% 23,550 268 6423,8827. Vejen 19,486 61.7% 12,109 38.3% 31,595 384 7832,0578. Vejle Nord 18,950 68.5% 8,722 31.5% 27,672 296 7828,0469. Vejle Syd 18,714 67.2% 9,147 32.8% 27,861 342 7528,27810. Fredericia 15,271 62.2% 9,268 37.8% 24,539 276 5924,87411. Kolding Nord 13,754 67.3% 6,697 32.7% 20,451 203 4320,69712. Kolding Syd 14,738 63.4% 8,502 36.6% 23,240 257 3523,53213. Haderslev 16,410 60.7% 10,609 39.3% 27,019 300 4327,362Central Denmark & North Denmark Regions 620,437 67.0% 306,232 33.0% 926,669 11,392 1,861939,922East Jutland 274,182 69.5% 120,265 30.5% 394,447 5,175 837400,4591. Århus Syd 30,136 74.6% 10,286 25.4% 40,422 598 10141,1212. Århus Vest 26,101 69.6% 11,390 30.4% 37,491 528 9538,1143. Århus Nord 29,341 71.8% 11,518 28.2% 40,859 719 12041,6984. Århus Øst 40,275 77.0% 12,063 23.0% 52,338 862 13253,3325. Djurs 26,056 65.1% 13,958 34.9% 40,014 374 7140,4596. Randers Nord 13,466 61.5% 8,435 38.5% 21,901 225 4622,1727. Randers Syd 15,418 64.2% 8,592 35.8% 24,010 243 4224,2958. Favrskov 17,104 69.4% 7,527 30.6% 24,631 257 4324,9319. Skanderborg 34,031 72.0% 13,214 28.0% 47,245 576 5347,87410. Horsens 27,296 64.7% 14,887 35.3% 42,183 479 9342,75511. Hedensted 14,958 64.1% 8,395 35.9% 23,353 314 4123,708West Jutland 168,770 66.3% 85,772 33.7% 254,542 3,092 465258,0991. Struer 13,526 65.6% 7,106 34.4% 20,632 226 4420,9022. Skive 14,251 62.8% 8,427 37.2% 22,678 277 3522,9903. Viborg Vest 16,218 66.8% 8,052 33.2% 24,270 332 5824,6604. Viborg Øst 14,892 67.1% 7,294 32.9% 22,186 268 4522,4995. Silkeborg Nord 15,996 67.2% 7,797 32.8% 23,793 296 4324,1326. Silkeborg Syd 18,202 71.5% 7,273 28.5% 25,475 325 4825,8487. Ikast 11,781 63.2% 6,866 36.8% 18,647 214 2918,8908. Herning Syd 12,471 65.7% 6,504 34.3% 18,975 215 3819,2289. Herning Nord 15,293 66.7% 7,638 33.3% 22,931 270 2323,22410. Holstebro 18,529 66.1% 9,482 33.9% 28,011 341 5128,40311. Ringkøbing 17,611 65.4% 9,333 34.6% 26,944 328 5127,323North Jutland 177,485 63.9% 100,195 36.1% 277,680 3,125 559281,3641. Frederikshavn 17,159 58.4% 12,245 41.6% 29,404 251 13029,7852. Hjørring 18,894 62.8% 11,187 37.2% 30,081 315 7230,4683. Brønderslev 22,239 62.3% 13,450 37.7% 35,689 421 5336,1634. Thisted 18,481 62.3% 11,168 37.7% 29,649 331 5530,0355. Himmerland 20,651 65.2% 11,014 34.8% 31,665 335 5432,0546. Mariagerfjord 12,339 61.9% 7,579 38.1% 19,918 197 4220,1577. Aalborg Øst 25,578 66.3% 12,987 33.7% 38,565 503 5539,1238. Aalborg Vest 21,855 69.0% 9,801 31.0% 31,656 401 4132,0989. Aalborg Nord 20,289 65.3% 10,764 34.7% 31,053 371 5731,481Denmark 1,848,242 66.9% 915,717 33.1% 2,763,959 32,739 5,8192,802,517Source: Denmark Statistics

Aftermath