(AP) — Vote counting in the union push at an Amazon warehouse in Bessemer, Alabama, is underway but a winner may not be determined until Friday.

By Thursday evening, the count was tilting heavily against the union, with 1,100 workers rejecting it and 463 voting in favor. The count will resume Friday morning.

The Retail, Wholesale and Department Store Union, which is organizing the Bessemer workers, said that 3,215 votes were sent in — about 55% of the nearly 6,000 workers who were eligible to vote. The union said hundreds of those votes were contested, mostly by Amazon, for various reasons such as the voter didn’t work there or doesn’t qualify to vote. The union would not specify how many votes were being contested.

The National Labor Relations Board is conducting the vote count in Birmingham, Alabama. In order to determine a winner, the margin of victory must be more than the number of contested votes, otherwise a hearing would be held on whether or not to open the contested votes and count them toward the final tally.

RWDSU President Stuart Appelbaum struck a grim tone Thursday in a statement ahead of the results: “Our system is broken, Amazon took full advantage of that, and we will be calling on the labor board to hold Amazon accountable for its illegal and egregious behavior during the campaign. But make no mistake about it; this still represents an important moment for working people and their voices will be heard.”

Amazon could not be reached for immediate comment.

The vote itself has garnered national attention, with professional athletes, Hollywood stars and even President Joe Biden weighing in on the side of the union.

If the union wins, it would be the first in Amazon’s 26-year history. But the vote also has wide-reaching implications beyond Amazon, which is now the second-largest private employer in the U.S. after retailer Walmart.

Whatever the outcome, labor organizers hope Bessemer will inspire thousands of workers nationwide — and not just at Amazon — to consider unionizing. For Amazon, which has more than 950,000 workers in the U.S. and has fought hard against organizing attempts, a union loss could chill similar efforts around the company.

The labor board has already reviewed each vote, reading names and signatures on the envelopes with representatives from Amazon and the retail union, both of which had a chance to contest those votes. Contested votes were put to the side and not opened.

Now the board is opening the uncontested votes from their envelopes and counting “yes” or “no” votes.

Even if there’s a clear winner, the battle may be far from over. If workers vote against forming a union, the retail union could file objections accusing Amazon of tainting the election in some way, which could lead to a redo of the election if the labor board agrees. Amazon could file its own objections if the workers vote to form a union.