BOSTON (Reuters) - Whole Foods has reached an agreement to settle a lawsuit accusing it of illegally firing a worker who refused to remove her Black Lives Matter facemask and complained about racism at the Amazon.com ( AMZN )-owned upscale grocery chain.

A lawyer for Whole Foods said in a filing on Monday in federal court in Boston it had reached an agreement in principle to resolve the case with Savannah Kinzer, an outspoken critic who had worked in a Cambridge, Massachusetts, store.

Her claims were the last that remained in a lawsuit that began as a proposed class action when it was filed in 2020 over a Whole Foods dress code that barred workers from wearing attire related to Black Lives Matter, a racial justice movement. A trial was set for Aug. 19.

Settlement terms were not disclosed. The company and Kinzer's lawyer did not respond to requests for comment.

The lawsuit stemmed from nationwide racial justice protests that followed the May 2020 killing of George Floyd, a Black man, under the knee of a white Minneapolis police officer.

During those protests, Whole Foods began disciplining employees who wore facemasks during the pandemic supporting Black Lives Matter.

Whole Foods cited its dress code, which it said was meant to foster a welcoming, safe and inclusive shopping environment. Kinzer and some other employees resisted, saying the company's dress code previously went unenforced.

Kinzer said she was then fired for protesting outside her store, rejecting demands to stop wearing a mask and talking to the press. She had also filed a complaint with the Equal Employment Opportunity Commission.

Kinzer and other employees sued in July 2020 shortly after her firing, arguing on behalf of other Whole Foods workers that the mask ban was racially discriminatory.

While courts rejected those discrimination claims, the Boston-based 1st U.S. Circuit Court of Appeals in April revived Kinzer's individual claim that her firing constituted illegal retaliation and said a jury should resolve the dispute.