Tens of thousands of Las Vegas hospitality workers may walk off the job this Friday if their union is unable to reach a contract deal with the casinos, hotels and restaurants that employ them.

What could possibly be the largest hospitality worker strike in U.S. history comes as the city is being transformed into a giant racetrack ahead of the Formula 1 Las Vegas Grand Prix scheduled to take place later this month — the first time the sport is returning to the entertainment capital in more than four decades.