The federal agency that enforces workplace civil rights laws has filed suit against Walmart, saying one of the company’s Colville store managers was discriminated against because he is Mormon.

The assistant manager, Richard Nichols, is also the mayor of Colville.

The Seattle office of the Equal Employment Opportunity Commission filed the suit Thursday, asking for a trial to determine damages suffered by Nichols, 65.

It said that Nichols – “a devout Mormon” – has been scheduled to work on Sundays, which violates his Mormon belief to refrain from all work on that day.

Nichols – who’s been mayor of Colville since 2004 – says in the suit that Walmart accommodated his Sunday-off request at a number of store locations from 1995 to 2009.

But in fall 2009, Nichols alleges, the Bentonville, Ark.-based retailer changed its scheduling system and refused to not schedule him for Sunday shifts.

Greg Rossiter, Walmart’s director of corporate communications, disputed the EEOC claim and said Nichols’ position is unfounded.

Walmart helps many of its employees avoid working on Sundays for religious beliefs, Rossiter said.

“We’re surprised by the charges because this associate has never had to work on Sunday,” he said.

Contacted Friday in Colville, Nichols referred all questions to EEOC attorneys.

Seattle EEOC attorney John Stanley said Nichols fears the company may fire him over his refusal to work on Sundays.

“I’m afraid I’ll be fired for choosing my religion over my work. It’s not a choice I want to have to make,” Nichols said in a prepared statement.

Stanley said Nichols observes the Sabbath by not working and by avoiding household chores or shopping.

Mormon leaders say Sundays should be devoted to family events or church activities.

The suit seeks unspecified lost wages and punitive damages, along with an injunction stopping Walmart from asking Nichols to work Sunday shifts. Stanley said the federal courts restrict awards for emotional distress and punitive damages to $300,000.