A bitter battle between doctors and a major cancer-care company that led to last-minute maneuvering in the Legislature is now heading to federal court.

21st Century Oncology, the state's largest provider of radiation oncology services, is asking a federal judge to block the state from enforcing a new law that would retroactively ban noncompete contracts the company entered into with five physicians.

The company filed the lawsuit Thursday, naming  Attorney General Ashley Moody and Secretary of State Laurel Lee as defendants. The company is seeking a temporary restraining order that would suspend the disputed part of the law and a preliminary injunction barring the state from enforcing it. The provision was tucked into a broader health-care bill in the waning days of the session.

“The last-minute addition appears to be a targeted attempt to invalidate existing non-compete agreements for a specific group of physicians,” one of the motions said.

Attorneys argue that the new law violates federal and state constitutional protections to enter into contracts.

The lawsuit came months after a group of physicians sued 21st Century Oncology. The Fort Myers News-Press reported that the physicians contend “the cancer-care provider acts as a 'monopoly' by employing all radiation oncologists in Lee, Collier and Charlotte counties and, through restrictive contracts, prevents them from leaving and competing against them.”

The provision inserted in the new law (HB 843) retroactively bans no-compete clauses for Florida-licensed doctors who practice a medical specialty in a county where one company contracts with all the physicians who practice in that specialty. The law bans restrictive contracts for three years after a second company comes into the county and starts providing the care.

If not enjoined, attorneys for the company argued in the complaint, the law would allow the five physicians to “dramatically alter the substantive rights of the contracting parties by reaching back into the agreements, removing one of the key bargained-for provisions.”

21st Century Oncology operates multiple treatment centers. It is the largest provider of radiation oncology services in Florida, including in Lee County, where it is the only company currently providing the services.

Attorneys say there are nine physician contracts in Lee County that the company signed, including with four current employee-physicians and five former employee-physicians, that include restrictive covenants.

If not enjoined, 21st Century may be forced to  reconfigure its health-care model, including physician employment, attorneys argued in the lawsuit.

The ban was tucked into one of several health-care bills that were negotiated behind closed doors. The bill, signed by Gov. Ron DeSantis, dealt with a  number of issues that range from allowing patients to stay overnight at ambulatory surgical centers to limiting HMOs and insurance companies from using “step therapy protocols” for prescription drugs in certain circumstances.

21st Century Oncology isn't the only provider impacted by the legislation. It also will affect hospitals in rural counties that usually seek similar contracts with physicians.

Vince Sica, chief executive officer of DeSoto Memorial Hospital in Arcadia, told The News Service of Florida last month that the ban will further stress the rural provider's ability to offer reliable specialty health care.

“Eliminating rural hospitals' ability to negotiate terms for private contracts with physicians would bring into health care all the worst problems associated with 'free agency' in professional sports,” he said. “Rural communities already struggle to attract and retain physicians. “

R.D. Williams, CEO of Hendry Regional Medical Center in Clewiston, agreed.

“If we cannot enforce our contracts with physicians, it may very well put us in a position where we cannot maintain the services that our community needs,” he said.

Christine Sexton reports for the News Service of Florida.