Amazon led by a wide margin in a vote over whether to unionize an Alabama warehouse, after several hours of counting ballots Thursday, but the final result is still up in the air in an election that may decide whether the site becomes Amazon's first organized workplace in the U.S.
Amazon is the second-largest private employer in America and unionizing it has been a goal of a U.S. labor movement seeing declining membership.
But with about half of the roughly 3,200 ballots counted on Thursday night, the tally is poised to reject unionization by more than a 2-to-1 margin.
Though sources told Reuters that roughly 500 of those ballots have been challenged, which could close the gap when vote counting continues on Friday.
Representatives for Amazon and the Retail, Wholesale and Department Store Union were able to question ballots on suspicion of tampering and voter eligibility, among other issues.
It wasn't clear how many votes each side challenged, but the union on Wednesday said hundreds were contested, mostly by Amazon.
The company had not commented on that claim.
If necessary, the U.S. National Labor Relations Board will formally determine the results of the election.