San Francisco, Feb 6 (IANS): Amazon's bid to postpone a union vote at a warehouse in the US state of Alabama has been rejected by the country's National Labor Relations Board (NLRB), clearing the way for 6,000 workers to decide whether to form a union.

Amazon appealed last month to prevent a mail-in vote by the warehouse workers on whether to join the Retail, Wholesale and Department Store Union.

The NLRB, in its ruling, said that Amazon's appeal raised "no substantial issues warranting review," CNBC reported on Friday.

"The Employer's Motion to Stay the Election Pending Review is also denied as moot," the board said.

The voting is being closely watched as it is the first major unionisation effort within Amazon since 2014 when similar efforts by repair technicians at a warehouse in Delaware failed as they could not get enough votes required for joining a union.

However, several events including the response to the Covid-19 pandemic and protests tied to Prime Day have sparked new unionisation efforts by the workers of the e-commerce giant.

The NLRB decision paves the way for the workers at the Bessemer, Alabama, warehouse to start voting by mail starting Monday.

NLRB's regional office needs to receive the ballots by March 29, and counting will start the following day.

In what appears to be a bid to discourage the union drive, Amazon has also set up a website reminding workers that joining a union will cost them money in the form of membership dues.