SAN FRANCISCO — Uber Technologies Inc. scored a major legal victory last year when a federal appeals court ruled that drivers who sued over background checks were bound by arbitration agreements they signed. On Wednesday, the company will try to hang on to that win.

On one side of the fight at the U.S. Court of Appeals for the Ninth Circuit is the lawyer representing drivers in a set of worker misclassification class actions, Shannon Liss-Riordan, and the National Labor Relations Board. They argue that notwithstanding last year's ruling, Uber's agreements are still unenforceable because they contain illegal collective action waivers.

Uber, represented by Theodore Boutrous Jr. of Gibson, Dunn & Crutcher, will be trying to smash the class actions once and for all. The company and its legal team have appealed every significant adverse ruling in those driver suits in district court, and Wednesday will be their chance to explain to the court why those decisions should all be rejected.