Germany's intelligence services had classified both the party and its youth organisation, Junge Alternative (JA), as suspected right-wing extremist groups.

A lower administrative court in Cologne, where the intelligence services are located, confirmed this assessment in 2022, allowing the office to monitor the party as a suspected case.

However, the party appealed the decision, which the Higher Administrative Court of North Rhine Westphalia located in Munster has now upheld.

The judgment is not yet legally binding. While the Munster court did not allow an appeal, the AfD can submit an application for authorisation to the Federal Administrative Court in Leipzig.

The AfD's signature issue is a hard-line anti-immigration stance, and the party is profiting from increased concern among many German voters over rising numbers seeking asylum in the country.

The party is polling nationally at around 20 per cent amid high dissatisfaction with Chancellor Olaf Scholz's three-party coalition.