Walmart is taking an unconventional approach to seasonal hiring this year by doing away with the longtime tradition of recruiting — and training — thousands of temporary workers for the holiday crush.

Instead, the world’s largest retailer says it will dole out extra holiday work to its existing employees.

“These extra hours will help staff traditional roles like cashier and stocker, and newly created positions such as personal shoppers and pickup associates,” Judith McKenna, chief operating officer for Walmart U.S., said in a statement. “This is what working in retail is all about, and we know our associates have the passion to do even more this year.”

Walmart employees and labor advocacy groups say the move could help address long-standing complaints among workers who say they are underemployed. Many part-time employees, they said, would like full-time work. Walmart considers 34 hours a week full time, which is when workers receive more benefits.

But, some labor advocacy groups say, the new policy raises questions: Will employees be forced to take on extra hours? Will they be penalized if they take time off during the holidays?

“The struggle to get enough hours has been the number one issue angering associates,” said Dan Schlademan, a spokesman for OUR Walmart, an employee group backed by the United Food and Commercial Workers Union. “We’ve never been able to understand why Walmart continues hiring seasonal workers when there are so many people begging them for more hours.”

Retailers have long relied on seasonal workers to get through the holidays. But with the national unemployment rate nearing a 16-year low, it is increasingly difficult to attract temporary workers for jobs that typically pay low wages.

As a result, Target, which plans to hire 100,000 seasonal workers this year, is raising its minimum wage to $11 an hour beginning next month. Toys R Us, which plans to hire more than 12,000 part-time workers despite filing for bankruptcy last week, says it will pay weekend rates during peak holiday times and offer additional employee discounts this year.

Economists and labor experts said Walmart’s new approach made financial sense for the company, which has 1 million hourly workers at its U.S. stores.

Some critics, though, raised concerns about the implications for workers.

“We’d like to see higher wages and more transparency around the program,” said Randy Parraz, director of Making Change at Walmart, a union-run campaign. “It’s one thing to offer more hours. It’s another thing to mandate them.”