Denmark to hold referendum on scrapping EU defence opt-out

Frederiksen also pledged to increase defence spending by 7bn kroner (£780m) over the next two years.

Participating in the common security and defence policy (CSDP) would enable Denmark to take part in joint EU military operations and to cooperate on the development and acquisition of military capabilities within the EU framework.

Sweden and Finland, which are not members of Nato, have both seen public support for joining the military alliance reach historically high levels since the start of the war, and this week both governments announced closer partnership with Nato and with each other on defence.

Meanwhile, the German chancellor, Olaf Scholz, overturned decades of defence policy by announcing a ¤100bn defence spending increase and sending weapons to Ukraine.

After the public rejected the Maastricht Treaty in June 1992, Copenhagen obtained opt-outs in four sovereign areas: the single currency, justice and police matters, defence and EU citizenship.

In December 2015, the Danes voted no to strengthening their cooperation with the European Union on police and security matters for fear of losing their sovereignty over immigration.