CNN Business  — 

Workers at an Amazon warehouse in Staten Island have shown enough support to hold a union election, the National Labor Relations Board (NLRB) confirmed on Wednesday.

For months, a grassroots group called Amazon Labor Union led by former Amazon employee Chris Smalls has worked to collect signatures from employees at the facility known as JFK8 to garner at least 30% of workers in support of unionizing.

Chris Smalls, a fired Amazon fulfillment center employee, center, holds a sign during a protest outside an facility in the Staten Island borough of New York, U.S., on Friday, May 1, 2020.

Just getting to this point is rare. While some Amazon (AMZN) workers are unionized in Europe, the company has so far fended off unions in the United States. Most notably and recently, a union push at an Amazon (AMZN) facility in Bessemer, Alabama, drew national attention from figures including Senators Elizabeth Warren and Bernie Sanders. The election, which took place by mail due to the ongoing pandemic, resulted in votes cast largely in the e-commerce giant’s favor. However, a federal labor official called for a re-election after finding the company improperly interfered. The re-election kicks off next week when workers will again receive their ballots by mail.

Unlike the Alabama-based Amazon workers who are organizing with the Retail, Wholesale and Department Store Union, the Amazon Labor Union is not affiliated with any established labor unions.

There have been just a few other efforts that have gotten to the point of meeting “a sufficient showing of interest,” as the Amazon Labor Union now has. There was an effort by Amazon workers to unionize at a facility in Virginia in 2015 that was withdrawn after reaching an election agreement; another resulted in an election at a Delaware warehouse in 2014 where just a small number of workers were eligible to vote, but ultimately rejected the effort.

An Amazon spokesperson was quick to cast doubt on Wednesday’s news. “We’re skeptical that there are a sufficient number of legitimate signatures and we’re seeking to understand how these signatures were verified,” said Amazon’s Kelly Nantel in a statement to CNN Business. “Our employees have always had a choice of whether or not to join a union.”

Amazon has until January 28 to file a statement of its position, which the Amazon Labor Union will then be able to respond to. A hearing is scheduled for February 16.

Tensions inside Amazon’s Staten Island facility have been evident for nearly two years, when workers, including Smalls, orchestrated a walkout to protest the company’s handling of the earliest days of the pandemic. Smalls was fired after the protest, which Amazon claims is because he violated its coronavirus protocols. Smalls said he was retaliated against for being vocal about workplace conditions.

On Thursday, the NLRB issued a complaint against Amazon concerning workers attempting to organize at the facility. The company is accused of having “repeatedly broke the law by threatening, surveilling, and interrogating their Staten Island warehouse workers who are engaged in a union organizing campaign,” according to a statement from the NLRB’s regional director Kathy Drew King.

A copy of the complaint viewed by CNN Business details alleged behavior that occurred last year by individuals at the facility that the NLRB says interfered with their rights to organize. That includes Amazon allegedly “telling employees that the Union organizing would fail because the Union organizers were ‘thugs,’” and prohibiting employees from distributing union literature.

In a statement Thursday, Amazon’s Nantel said: “These allegations are false and we look forward to showing that through this process.”

In December, Amazon and the NLRB agreed to a settlement that addresses one of the ways workers have said the company has thwarted organizing efforts more broadly: Limiting workers’ access to its facilities before or after shifts to just 15 minutes. As part of the settlement, Amazon is required to post its notice informing workers at its facilities of their rights. Also written into the agreement: the NLRB can now more quickly seek compliance from Amazon should it break the terms of the agreement.