A German court on Tuesday found a prominent far-right politician from the Alternative for Germany party guilty of using a banned Nazi slogan during a campaign speech in 2021.

A panel of four judges sentenced the politician, Björn Höcke, head of the Alternative for Germany party in the eastern state of Thuringia, to a fine of 13,000 euros, roughly $14,000. The trial, in the city of Halle, has been closely watched in Germany as the far-right nationalist party, known as the AfD, stands to make major gains in state elections in September.

During the trial, which began last month, Mr. Höcke admitted to using the phrase “Everything for Germany” but claimed that he had not known about its Nazi origin. The slogan was used by the paramilitary wing of the Nazi party, which engraved it on their knives.

But the fact that Mr. Höcke was previously a high school history teacher and that his party has repeatedly run into legal trouble for using the exact same phrase seemed to undermine his argument, leading to the court’s ruling.

Using Nazi phrases, gestures, symbols or uniforms is against the law in Germany and is punishable by up to three years in prison. However, the court had said earlier that it would not seek a prison sentence.

The verdict comes months before an election for the Thuringian legislature that could, for the first time since the end of the Nazi regime in 1945, put a far-right party in control of a state government.

The AfD, which is now polling at 30 percent, could technically win enough seats in the legislature to be able to run the state government, which would allow Mr. Höcke to assume a position equivalent to a governor.

A German court on Tuesday found a prominent far-right politician from the Alternative for Germany party guilty of using a banned Nazi slogan during a campaign speech in 2021.

A panel of four judges sentenced the politician, Björn Höcke, head of the Alternative for Germany party in the eastern state of Thuringia, to a fine of 13,000 euros, roughly $14,000. The trial, in the city of Halle, has been closely watched in Germany as the far-right nationalist party, known as the AfD, stands to make major gains in state elections in September.

During the trial, which began last month, Mr. Höcke admitted to using the phrase “Everything for Germany” but claimed that he had not known about its Nazi origin. The slogan was used by the paramilitary wing of the Nazi party, which engraved it on their knives.

But the fact that Mr. Höcke was previously a high school history teacher and that his party has repeatedly run into legal trouble for using the exact same phrase seemed to undermine his argument, leading to the court’s ruling.

Using Nazi phrases, gestures, symbols or uniforms is against the law in Germany and is punishable by up to three years in prison. However, the court had said earlier that it would not seek a prison sentence.

The verdict comes months before an election for the Thuringian legislature that could, for the first time since the end of the Nazi regime in 1945, put a far-right party in control of a state government.

The AfD, which is now polling at 30 percent, could technically win enough seats in the legislature to be able to run the state government, which would allow Mr. Höcke to assume a position equivalent to a governor.