A new coalition of major unions, consumer rights groups and gay activists yesterday endorsed a controversial D.C. health care licensing bill that proponents contend will help to stem mounting hospital costs by sparking competition within the medical profession.

The precedent-setting bill, introduced by City Council member Polly Shackleton (D-Ward 3), would open up city hospital facilities to nurse-midwives, nurse-practitioners, nurse-anesthetists, psychologists and podiatrists in an attempt to give patients health-care alternatives not now available.

Joslyn N. Williams, president of the AFL-CIO's Metropolitan Washington Council and a chief spokesman for the health care coalition, harshly criticized the D.C. Medical Society for seeking to defeat or weaken the measure.

Williams said at a press conference at the District Building that medical society members are interested primarily in "maintaining a stranglehold on access to facilities and in preserving their dominant market position.

"We think there is just a plain-out conspiracy of doctors and hospitals to keep these competing groups out," Williams said.

He was joined by representatives of the National Consumers League, the Washington Urban League, the Metropolitan Washington Gray Panthers, the Gay Activists Alliance and the Coalition of 100 Black Women of D.C.

Dr. Dennis S. O'Leary, president of the medical society, said his group's opposition to the bill stems from legitimate "public policy" concerns about patients' welfare, and not from the self-interest of physicians.

"I know Josh Williams and he has no substantial basis for making those comments," O'Leary said.

Shackleton's bill was approved by the council's Human Services Committee July 7 and is scheduled to be considered today by the Committee of the Whole.

The medical society is seeking an amendment that would require that nurse-midwives, nurse-anesthetists and nurse-practitioners obtain District licenses to practice their individual specialties in city hospitals.

Such licenses would be in addition to the general licenses that registered nurses currently must obtain from the city.

The society also has objected to a provision that for the first time would allow psychologists to take part in determining whether to hospitalize a patient for a mental illness. Unlike psychiatrists, psychologists do not hold medical degrees.

"The majority of psychologists are not trained to perform the difficult tasks which they would assume," O'Leary said in a recent letter to Shackleton, who is chairman of the Human Services Committee.

"Psychologists have no training in the prescription and management of medication--a critical treatment adjunct which can eliminate the need for hospitalization," O'Leary wrote. "Further, psychologists are not trained to distinguish between physical and mental causes of psychiatric illness."

Jeff Levi, president of the Gay Activists Alliance, said he supports the provision, noting that psychologists traditionally "have been more willing than the psychiatric profession to treat gay patients."

"The more traditional medical establishment is not as aware or focused on our health needs," Levi said.