Workers at an Amazon warehouse in Bessemer, Alabama, have voted resoundingly against unionisation, a major blow to the US labour movement and its hopes of gaining a foothold within the ecommerce giant.

Around 55 per cent of the facility’s almost 6,000 workers cast a postal ballot. The “no” vote passed the required threshold of 1,607 on Friday morning.

Around 500 votes submitted have been challenged by both Amazon and the union, but they are not expected to have a bearing on the result, with votes against unionisation coming in at a rate of more than two-to-one.

The Retail Wholesale and Department Store Union (RWDSU) has said it will appeal against the decision, citing what it said were numerous and egregious efforts to illegally influence the vote.

“Amazon knew full well that unless they did everything they possibly could, even illegal activity, their workers would have continued supporting the union,” said Stuart Appelbaum, RWDSU president.

The National Retail Federation, a US-based industry organisation, said in a statement: “Union representation is a choice for workers, but many clearly prefer opportunities in a competitive marketplace that provides strong wages and benefits over the anonymity of a collective bargaining agreement.”

Amazon has not yet responded to the result.