Denver is smoking mad over the “enormous quantities” of cigarette butts littering its public places — so it's suing Big Tobacco to help pay for the cleanup.

In a 72-page lawsuit, the Mile High City accuses 10 cigarette companies of creating a “public nuisance” by selling smokes with environmentally “persistent” synthetic plastic filters instead of biodegradable ones.

“We want to make sure that they pay their fair share of the cost that cities are bearing to clean up their mess and that we want to see them change the practice," Mayor Mike Johnston told the Denverite website.

The World Health Organization estimates that 4.5 trillion cigarette butts are tossed away in public annually, and Johnston said research suggests they account for up to one-quarter of Denver’s litter problem.

The defendants named in the city’s lawsuit include tobacco giants Philip Morris USA, manufacturer of the top-selling Marlboro brand, and R.J. Reynolds Tobacco Co., which makes Camel, Newport and Pall Mall cigarettes.

None of the companies immediately returned inquiries Wednesday from The Independent.

Denver's lawsuit begins by citing the Philip Morris International website, which says in part, “By 2030 there could be more cigarette butts than fish in the oceans.”

The complaint alleges that discarded butts have piled up around the city on “streets, sidewalks, parks, public rights-of-way, parking areas, public facilities, stormwater infrastructure, drainage systems, waterways, and other publicly owned or maintained property.”

“Denver does not allege that a single discarded cigarette filter, standing alone, caused the injuries at issue,” court papers say. “Rather, the physical condition affecting Denver-owned or maintained property and infrastructure results from the continuing accumulation of enormous quantities of discarded cigarette filters introduced into Denver through Defendants’ respective commercial activities.”

The lawsuit demands unspecified damages on grounds that include negligence, product liability and alleged violations of the Colorado Consumer Protection Act.

It also seeks a court order requiring that the defendants take "reasonable measures to prevent, reduce, manage, remove, or remediate continuing cigarette-filter impacts."

The complaint doesn't cite the city's cost of cleaning up the butts, and a mayoral spokesperson didn't immediately return an inquiry from The Independent.

Denver's legal action follows similar moves by Baltimore and Sacramento County, California, according to Denverite.

Johnston said city officials spent about a year deciding whether to file the lawsuit, which it outsourced to law firms in Denver; Overland Park, Kansas; and West Islip, New York.

“All of our city attorneys are working every day on day-to-day enforcement around the city,” Johnston told Denverite. “We didn't have a lot of bandwidth to spend to bring a national suit like this, but we think it's the right one to bring and are delighted to have partners to help us do it.”