NEW YORK (AP) — The National Labor Relations Board said there was enough interest to form a union at an Amazon distribution center in New York, after union organizers on Monday delivered hundreds of signatures to the agency — a key step in authorizing a vote that could establish the first union at the nation’s largest online retailer.

It would be the second unionizing attempt in the past year at Amazon. Workers in Alabama resoundingly defeated an effort earlier this year, but organizers there are asking federal officials for a do-over.

Organizers delivered more than 2,000 signed union-support cards to the NLRB’s Brooklyn office after launching the effort in April. The specific number of signatures was not immediately available.

“This is a small victory,” said Christian Smalls, a former employee of the retail giant who now leads the fledgling Amazon Labor Union, adding, “We know the fight has just started.”

An Amazon spokesperson did not immediately respond to a request for comment.

Monday’s development puts the company on notice that the NLRB has determined that union organizers have met the minimum threshold for Amazon to formally acknowledge and to respond to the union-organizing petition. That means the company must post notice on its premises that the union is seeking to become the bargaining representative for thousands of Amazon workers on Staten Island.

The company could have several avenues to challenge the effort, including contesting the number of employees that union organizers used to calculate the minimum signatures they needed.

“This was the easy part. Convincing at least 50% of the workers to vote yes is the hard part,” Smalls said afterward.

NLRB staff members started counting the cards soon after they were delivered, and union organizers were confident that they had met the minimum necessary. They had planned a rally outside the Staten Island distribution center Monday evening.

If organizers in New York succeed, it could launch other union drives across the company’s vast empire, which includes more than 100 fulfillment centers and nearly 1 million employees across the United States.

Smalls says he was fired last year after organizing a walkout to protest working conditions, although the company said he repeatedly violated company policies.

The NLRB must now verify the submitted signatures to confirm if organizers collected the requisite number of signatures — at least 30% from the roughly 5,500 employees who the union says work at four adjoining Amazon facilities — to authorize a union vote.

The company could challenge the effort by contesting how the number of employees union organizers used to calculate the minimum number of signatures they required.

Amazon employees have complained about long work hours, insufficient breaks and safety, with Smalls and others likening working conditions to modern-day sweatshops. The employee turnover rate has also been a cause of concern.

The union efforts on Staten Island come as Amazon is on a hiring binge. It announced in September it wants to hire 125,000 delivery and warehouse workers and is paying new recruits an average of $18 an hour in a tight job market. That’s in addition to the 150,000 seasonal workers it plans to bring on this season.

The Retail, Wholesale and Department Store Union had led the effort to form a union at the Alabama facility that was defeated in April.

A hearing officer for the NLRB found in August that Amazon potentially interfered with the Alabama election. And the RWDSU is now waiting for a decision from an NLRB regional director to see whether the hearing officer’s guidance will be sanctioned. But even with a second election, labor experts say a union victory is a long shot.

The New York City organizing drive is taking place without the support of a national union.