WASHINGTON — The bitter standoff between Wal-Mart and Washington, D.C. officials over the city's effort to impose a higher minimum wage on big-box retailers is fueling a wider debate about how far cities should go in trying to raise pay for low-wage workers — and whether larger companies should be required to pay more.

Wal-Mart, the nation's largest private employer, is fuming about a "living wage" bill approved by the D.C. Council that has an unusual twist — it would apply only to certain large retailers, forcing them to pay employees at least $12.50 an hour. That's nearly 50 percent higher than city's minimum wage of $8.25 an hour.

The measure is being cheered by unions and worker advocates who have long complained about Wal-Mart's wages and working conditions. Opponents call it an unfair tactic that will discourage companies from doing business in the city.