Members of the Denver City Council unanimously approved an ordinance Monday that prohibits law enforcement officers, including federal immigration agents, from wearing a mask or face covering while interrogating, detaining, or arresting an individual within Denver, including in city-owned buildings.

The measure, which amends Chapter 28 of the Denver Revised Municipal Code, also sets a standard for officers to show their identity upon request.

Situations requiring a face covering for occupational health and safety, as well as undercover assignments, would be exempt.

“Anyone granted the authority to use deadly force must be held to the highest standard of accountability that starts with transparency,” Denver City Councilmember Chris Hinds said. “The public has a right to know who is exercising that power. If someone cannot do the job without hiding their identity, then they should not be entrusted with the responsibility to take a human life.”

The move comes just days after Denver Mayor Mike Johnston outlined his city’s response to civil immigration enforcement operations, including intervening to stop federal officers when local police observe them using “excessive” force.

The order also bans civil immigration enforcement activities on city-owned or city-operated property, which could include parks and facilities such as the National Western Complex.

The mayor’s move is the latest in a string of proposals from Democrats, who have begun to position the state and jurisdictions they dominate in a more confrontational stance. The attorney general, for example, wants residents to report alleged misconduct by federal agents via an online tool. At the state Capitol, legislators are considering a proposal to allow a “cause of action” by individuals injured — presumably by federal agents — in an immigration enforcement action.

Both Denver and Colorado have long adopted “sanctuary” policies, which refer to laws or ordinances that limit or prohibit cooperation with federal immigration authorities.

What the Denver mayor outlined, however, sets a new phase in the tension between the federal government and the city — since the new mandates, directed at city workers, are more active. That is, they require city employees, notably the police, to actively insert themselves into ongoing enforcement operations, whereas current laws prohibit cooperation.

As for the mask ban, supporters said it would help protect the rights of immigrants, address public safety fears and increase transparency. Meanwhile, some warned of complications arising from local police confronting federal agents while conducting operations here.

“Our main concern with the proposed ordinance is enforcement, and how that’s going to affect the Denver police officers if they do have to take an enforcement action against a federal agent. The concern is also possible conflict with other federal agents,” Brian Pacelko, president of the Denver Police Protective Association, said at a hearing last month.

Denver City Councilmember Flor Alvidrez called the legislation “literally the bare minimum that we can do.”

“And we’ve said that over and over again — this isn’t the greatest legislation ever passed to protect immigrant rights. This is literally trying to find the bare minimum that we can do to help people have some sense of safety and security in our city,” she sad.

Councilmember Paul Kashmann added, “One of the first lessons I learned as a child was that bad men wear masks. Someone comes up to my car with a mask and a gun, I don’t care what it says on their shirt or coat; I’m not opening the door, and certainly not answering it at my home, to someone wearing a mask.”

Johnston’s order may be more symbolic than enforceable.

On Friday, ICE said local officials cannot prohibit federal agents from operating from public properties.

“This is legally illiterate. No local official has the authority to bar ICE from carrying out federal law on public property — just as they cannot bar the media from reporting on city streets. Enforcing federal immigration laws is a clear federal responsibility under Article I, Article II and the Supremacy Clause,” ICE said in a statement.

“While Mayor Johnston continues to release pedophiles, rapists, gang members, and murderers onto their streets, our brave law enforcement will continue to risk their lives to arrest these heinous criminals and make Denver safe again,” the agency added.

Denver Gazette news partner 9NEWS contributed to this story. To read more, visit 9NEWS.com