Amazon on Friday lost its push to postpone a union vote at an Alabama warehouse, allowing 6,000 workers to decide the first major unionization effort within the company since 2014.

The National Labor Relations Board denied Amazon’s motion to delay the vote at the Bessemer, Alabama, warehouse slated for Monday.

Last month, Amazon filed a motion with the U.S. labor board to delay the vote and give the board more time to reconsider an earlier decision to hold the election by mail.

Amazon pressed for an in-person election, citing flaws in the agency’s definition of what constitutes a coronavirus outbreak.

By denying Amazon’s appeal, the NLRB will allow Amazon workers at the warehouse to begin voting by mail starting Monday. Ballots must be received by the NLRB’s regional office by March 29, and counting will begin the following day.