The city council unanimously approved the wage increase at Tuesday's meeting. The ordinance was tentatively approved, and a final vote is scheduled for Feb. 2.
"Taking a moment in-between watching inaugural events to sign a $4 an hour pay increase for grocery and supermarket workers. You have earned this hero pay. Thank you for your hard work," Mayor Robert Garcia tweeted Wednesday.
RELATED: Long Beach passes resolution backing hazard pay for grocery workers
Long Beach City Council passes resolution giving grocery workers extra $4 per hour in hazard pay
The wage increase will apply to companies with 300 employees or more nationwide and more than 15 employees per store in Long Beach. It will be in place for at least 120 days.
Opponents say the ordinance was rushed and not studied enough.
The California Grocers Association Wednesday filed a legal challenge to the ordinance.
The CGA lawsuit, filed in Los Angeles federal court, asks the court to declare the pending hazard pay decree invalid and unconstitutional. The CGA also is seeking a preliminary injunction to stop implementation of the ordinance until a judge can rule on the merits of its lawsuit.
The CGA alleges that the ordinance is illegal because, by singling out certain grocers and ignoring other groups that employ essential frontline workers, it violates the constitutional requirement that similarly situated people must be treated alike.
The CGA also argues that the ordinance is preempted by the federal National Labor Relations Act, which protects the integrity of the collective-bargaining process.
City News Service contributed to this report.