A US labor board found that Amazon wrongly fired two employees who were part of an activist group called Amazon Employees for Climate Justice

US labor regulators on Monday sided with two Amazon workers who claimed they were improperly fired after calling on the company to do more to protect workers and the environment.

The National Labor Relations Board said that it found merit in claims made by dismissed Amazon employees Emily Cunningham and Maren Costa, outspoken critics of Amazon who were fired last year.

"One little thing is right in the world today," read a Twitter post by Costa that included a link to a New York Times story on the news.

The NLRB confirmed the report to AFP, saying its director will file an unfair labor practice complaint against Amazon if it doesn't settle the matter with Cunningham and Costa.

Costa and Cunningham worked as designers at Amazon's Seattle headquarters before being fired a year ago, according to the report.

They were part of a group called Amazon Employees for Climate Justice.

In her Twitter profile, Cunningham describes herself as a founding member of the group who was "fired for raising the alarm about climate and Covid-19."

Amazon disputed the version of events.

"We support every employee's right to criticize their employer's working conditions, but that does not come with blanket immunity against our internal policies, all of which are lawful," said an Amazon statement to AFP.

"We terminated these employees not for talking publicly about working conditions, safety, or sustainability, but rather, for repeatedly violating internal policies."

The NLRB news came as votes by Amazon employees in Alabama are being counted to see if a warehouse there will become the first union shop at the e-commerce colossus.

Tally of the ballots, which have been cast by mail since February 8, will take place behind closed doors, overseen by the NLRB.