The mayor of San Diego, California has ordered city officials to discard a new rule that prohibits employees from using "Founding Fathers" and other terms perceived as "gender biased."

In the "Bias-Free Language" section of its "Visual and Correspondence Style Guidelines," the city earlier ordered employees not to use "gender-biased" words and phrases including "the common man," "manmade," and "man up."

For "Founding Fathers," it told to use "founders" instead. It also urged employees preparing official reports to disregard or paraphrase research that contains such biased language.

Pacific Justice Institute (PJI) sent a letter to Mayor Kevin Faulconer on Monday asking the rule to be rescinded.

In the letter, PJI lawyer Matthew McReynolds reminded the mayor that more than 1,500 Supreme Court and lower court decisions have directly invoked Founding Fathers.

"At a time set aside to honor American icons to whom we owe our constitutional freedoms, it is offensive and indefensible that the City of San Diego is directing employees not to even mention the Founding Fathers," said Brad Dacus, the institute's president, in a statement.

He added, "We are calling on the mayor to immediately retract these guidelines and reassure city employees that they will not be punished for being patriotic. We cannot allow this type of censorship and PC insanity to destroy our free speech."

In response, Mayor Faulconer posted on Facebook, "Suggesting that our Founding Fathers should be referred to as 'Founders' is political correctness run amok."

"We are proud of our nation's history and there is nothing wrong with referring to the Founding Fathers. At my direction this was removed yesterday from the City's correspondence manual. The manual will be reviewed for other misguided examples that defy common sense and changes will be made accordingly," he added.

McReynolds told the mayor that "the folly of the prohibition is so self-evident that we will offer to represent, at no charge, any city employee who is disciplined or admonished for invoking our Founding Fathers."

City spokesperson Katie Keach said it won't happen.

"No employee has ever been disciplined for referencing our Founding Fathers, and no one ever will," she said, according to Fox News.