The Teamsters said workers will began striking at Amazon facilities across the country Thursday morning — in what the union calls the largest strike against the online shopping giant less than a week before Christmas.

The Teamsters said the strike began early Thursday at several facilities, including in New York City, Atlanta, three locations in Southern California, one in San Francisco and one in Skokie, Illinois.

In addition, the Teamsters said local unions would also put up primary picket lines at hundreds of Amazon Fulfillment Centers nationwide.

In a news release, the union calls it the “largest strike against Amazon in U.S. history” and says it comes after Amazon has refused to bargain with workers organized with the Teamsters.

“If your package is delayed during the holidays, you can blame Amazon’s insatiable greed,” said Teamsters General President Sean M. O’Brien in a statement. “We gave Amazon a clear deadline to come to the table and do right by our members. They ignored it.”

In a statement to ABC News, an Amazon spokesperson said the Teamsters have illegally coerced workers to join the union.