US President Donald Trump has called for a boycott of American tyre company Goodyear, stoking a controversy over political expression in the workplace.
The attack followed reports the firm had forbidden staff from wearing Trump campaign gear, while allowing "Black Lives Matter" and gay rights attire.
Goodyear said its rules forbid activism that falls "outside the scope of racial justice and equity issues".
The tyre-maker said its goal was an "inclusive, respectful workplace".
The firm's shares slumped as much as 6% following the president's attack but later regained ground.
Goodyear is the largest tyre company in North America. Its branded tyres were on 24% of new vehicles in the United States in 2018, according to Tyre Business, an industry publication.
It drew the president's ire after a report from a Kansas news outlet, based on a slide from a presentation, which had been shared by an employee.
The slide outlined what was "acceptable" and "unacceptable", with gear bearing the Trump campaign slogan "Make America Great Again" and "All Lives Matter" statements in the latter category.
Goodyear defended its policies on Wednesday, but said the slide in question had not been prepared at headquarters. It also said it did not indicate an "anti-police" stance.
"Goodyear has always wholeheartedly supported both equality and law enforcement and will continue to do so," it said. "These are not mutually exclusive."
Democratic Senator Sherrod Brown, who represents Ohio, the midwestern state where Goodyear is based, said the president's call for a boycott was "despicable".
Political battles
Goodyear is not the first company to find itself caught in the crosshairs of America's heated battles over politics and race.
Image copyright Goya Foods Image caption Goya Foods is the largest Hispanic-owned food company in the USAmazon last month was sued by employees who said the company had discriminated against them by punishing them for wearing Black Lives Matter gear in a selective enforcement of its dress code.
Democratic lawmakers also called for a boycott of Goya Foods, a Hispanic-owned food company known for its canned beans, after its chief executive expressed support for the president.
Earlier consumer campaigns have pressured companies to cut ties with the National Rifle Association and leave business councils advising the Trump administration.
Mr Trump has also frequently used Twitter to express his unhappiness with companies such as Amazon and General Motors.
In his tweet about Goodyear on Wednesday, he appeared to allude to the consumer boycotts championed by Democrats, saying "two can play that game".
"Don't buy GOODYEAR TYRES - They announced a BAN ON MAGA HATS. Get better tyres for far less!" he urged.