Denmark's left-leaning Social Democratic Party has unanimously elected former Justice Minister Mette Frederiksen as its interim head.

The 37-year-old Frederiksen is expected to be formally tapped next weekend to replace Helle Thorning-Schmidt, who stepped down as prime minister and party leader following Thursday's election defeat.

The vote for Frederiksen Saturday was expected since she has long been considered the party's crown princess.

The Social Democratic Party lost power in the parliamentary election to the country's center-right bloc, led by Liberal Party head Lars Loekke Rasmussen.

To form a government, Loekke Rasmussen has started talks with possible coalition partners, including the populist, anti-immigration Danish People's Party that demands reinstating border controls with Germany and Sweden.