Tesla Inc.’s registrations plummeted in Germany last month as Chief Executive Officer Elon Musk irked voters taking part in the country’s closely contested federal election.

February numbers show the U.S. electric-car maker is struggling to attract buyers in the region. Mr. Musk’s politics aren’t helping.

Tesla car sales in Germany fell by 76% in February, data showed on Wednesday, adding to the collapse in sales of Elon Musk's EV brand across Europe in what could be a loyalty test for the close ally of U.