Amazon has applied to a court to overturn the result of a vote by its workers to be represented by a trades union. According to the US National Labour Relations Board (NLRB) this has potential to be successful.

According to Reuters, the online retailer has lately accused the Brooklyn office of the NLRB of supporting the union drive. At the same time it has alleged that organisers intimidated workers to vote in support of unionisation. Both have denied these.

Citing the Brooklyn office’s alleged behaviour, Amazon successfully had the case moved to the Phoenix, AZ NLRB office to be heard. The Phoenix office’s director, Cornele Overstreet, said the evidence behind Amazon’s claims “could be grounds for overturning the election,” according to a filing on Friday.

In the vote, 55% of those employees who voted at the JFK8 warehouse on Staten Island voted to join the Amazon Labor Union (ALU). The turnout was about 58%. This was an important vote as it marked the first time Amazon workers in the US had voted to unionise. As the US’s second largest private employer this amounts to an important step for organised labour there.

Of the 25 objections made to the vote by Amazon to the Phoenix NLRB, Overstreet did not say which would likely invalidate the election’s outcome. The hearing is to be on May 23rd, after which the hearing officer will pronounce judgment some weeks later.

Eric Milner, an attorney for the ALU, said the bar to get a hearing is “very low” and no official had vetted Amazon’s alleged evidence yet. “While the ALU is disappointed in any delay by Amazon in its bargaining obligations we remain confident that all of Amazon’s objections will ultimately be overruled,” he said.

Amazon spokesperson Kelly Nantel said, “We want our employees to have their voices heard, and in this case, that didn’t happen – fewer than a third of the employees at the site voted for the union.”