Thousands of Amazon.com workers will walk off the job on Thursday at 6 a.m. ET (1100 GMT), in the crucial final days of the holiday season, after union officials said the retailer failed to come to the bargaining table. The International Brotherhood of Teamsters said unionized workers at facilities in New York City; Skokie, Illinois; Atlanta, San Francisco and southern California will join the picket line to seek contracts guaranteeing better wages and work conditions. The Teamsters union has said it represents about 10,000 workers at 10 of the company's U.S. facilities, representing about 1% of Amazon's hourly workforce. Among them, seven will walk out on Thursday, the Teamsters said.

The strike could disrupt Amazon's operations as it races to fulfill orders during its busiest season of the year. In the New York City area, however, the company has multiple warehouses, as well as smaller delivery depots for fast same-day delivery. Amazon did not immediately respond to a Reuters request for comment. The union had given Amazon a deadline of Sunday to begin negotiations, and workers at facilities voted recently to authorize a strike. Teamsters local unions are also putting up primary picket lines at hundreds of Amazon Fulfillment Centers nationwide, the union said in a statement on Wednesday.

Observers said Amazon is unlikely to come to the table to bargain, as it could open the door to additional union actions.

“Amazon clearly has developed a strategy of ignoring their workers’ rights to collectively organize and negotiate,” said Benjamin Sachs, a Harvard Law School professor of labor and industry.

He noted that more than two years after workers at a Staten Island warehouse became the first in the United States to vote to unionize, Amazon has still not recognized the group.

Amazon has, however, filed objections with the National Labor Relations Board (NLRB) over the 2022 Staten Island election, alleging bias among agency officials, among other issues. Further, Amazon challenged the constitutionality of the NLRB itself in a September federal lawsuit.

The Seattle-based company has also said the Teamsters "attempted to coerce" workers illegally to join the union.

The Teamsters said the Staten Island warehouse could join the strike at any time, as well as another southern California facility that had earlier voted to join the walkout.

In recent years, Amazon.com has faced worker walkouts in Spain and Germany, among other regions, over pay and working conditions. As the world's second-largest private employer after Walmart , Amazon has long been a target for unions. Some workers have said Amazon's emphasis on greater speed and efficiency can lead to injuries, while Amazon has said it pays industry-leading wages and regularly introduces automation designed to reduce repetitive stress. The company will face other union actions in the months ahead. Workers at a Philadelphia Whole Foods in November filed to hold a union election, the first since Amazon acquired the grocery chain in 2017.

Last month, an administrative judge ordered a third union election at an Alabama warehouse after ruling Amazon had acted unlawfully to thwart unionization there. Earlier this year, Amazon announced a $2.1 billion investment to raise pay for fulfillment and transportation employees in the U.S., increasing base wages for employees by at least $1.50 to around $22 per hour, a roughly 7% increase.