NEW YORK: US regulators are expected to start tallying votes in Amazon.com Inc's closely watched union election in Alabama later on Thursday or early Friday, union officials said.

The elections had voter turnout of about 55% the Retail, Wholesale and Department Store Union (RWDSU) said in a statement on Wednesday.

More than 3,200 mail ballots were received by the US National Labor Relations Board (NLRB), in an election open to over 5,800 workers at Amazon's warehouse in Bessemer, Alabama, the union said. The workers are voting on whether to join the RWDSU and have their warehouse be the first Amazon facility ever to unionize in the United States.

By comparison, 432 other mail-ballot elections from mid-March 2020 through September 2020 saw turnout of 72%, according to data disclosed by the NLRB in a decision last year. In the nearly six months prior to that - pre-dating the COVID-19 outbreak in the United States - mail-ballot turnout was 55%, the NLRB decision document said.