BERLIN - Germany's Office for the Protection of the Constitution may monitor the right-wing Alternative for Germany (AfD) party as a "suspected extremist", the Higher Administrative Court of North Rhine-Westphalia ruled on Monday.

The court rejected an appeal by the party and confirmed an earlier ruling from 2022. There was a "well-founded suspicion" that at least a significant part of AfD members were seeking to give German nationals with a migration background a "legally devalued status," the court found.

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The AfD has already announced that it will escalate the legal dispute with a higher court. "It is incomprehensible that the Senate did not allow the appeal, even though we debated complex legal issues for days," said Roman Reusch, a member of the AfD federal executive board, in a statement.

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The right-wing party has been the second-strongest force in the polls for months, but support among voters is dwindling. Compared to the beginning of the year, the AfD lost 6 percentage points and is currently at 17 percent, according to an Insa survey on the upcoming European elections.

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In the three eastern German states of Thuringia, Saxony, and Brandenburg, where there will be state elections this year, the AfD remains in the lead with poll scores of around 30 percent, according to the latest polls.