Danish women now face being called up for 11 months of military service when they turn 18, after a change in the law came into effect.

Under new rules passed by Denmark’s parliament, women are to join teenage males in a lottery system that could require them to undertake a period of conscription.

The change was brought in as Nato countries boost defence spending amid heightened security concerns in Europe.

Up to now, women were allowed to participate in military service when they turned 18, but on a voluntary basis.

From Tuesday, both men and women turning 18 will be required to register to be assessed for potential military service. Volunteers will be recruited first, with the remaining numbers made up through the lottery system.

The change will also see the period of conscription for teenagers rise from four months to 11 months.

About 4,700 Danish men and women undertook a short period of military service in 2024 – about 24% of them being female volunteers. The new rules on conscription are expected to see the overall number doing military service annually rise to 6,500 by 2033.

Denmark is following the example of neighbouring Sweden and Norway, which both brought in conscription for women in recent years.

The government in March also announced a 40.5bn Danish crowns (£4.3bn, $5.9bn) increase in defence spending over the next five years to meet Nato targets.

There are about 9,000 professional personnel currently serving in Denmark’s military.

Colonel Kenneth Strom, head of the Danish military’s conscription programme, said the change was “based on a political decision and a political agreement made by the parties”.

He added: “And obviously, it’s based on the current security situation in order to get more combat power and have those skills that are needed for either the Army, Navy, Air Force or even the Special Operations Forces.”

Speaking to the Reuters news agency, Katrine, a current volunteer in Denmark’s military, said: “In the world situation we’re in right now, it’s necessary to have more conscripts, and I think that women should contribute to that equally, as men do.

“I think it’s a positive change.”