D.C. firefighters mounted a two-pronged constitutional challenge yesterday to departmental regulations that limit what they can say to the news media, restrict the kinds of bumper stickers they may have on their cars and permit disciplinary action for nonpayment of bills.

Attorneys for the firefighters asked Judge Barrington D. Parker in U.S. District Court here to find that the regulations are in violation of his 1976 order declaring that similar restrictions violated public employes' First Amendment rights.

At the same time, five firefighters and their union, Local 36 of the Fire Fighters Association, filed a new suit seeking the rescinding of administrative actions taken against two firefighters for talking with local television reporters.

The suit, which seeks damages, also challenges administrative action taken against three other firefighters for displaying bumper stickers that read "D.C. Fire Department -- It's Not Just a Job, It's a Joke Too!"

The suit alleges that the regulations are designed to intimidate and deter firefighters from exercising their rights under the First Amendment, which guarantees freedom of expression, and the Fifth Amendment, which guarantees due process of law and protects individuals from self-incrimination.

"I think the facts show that the District's pattern of conduct seems to be aimed at penalizing firefighters who engage in freedom of expression," said Lee Levine, an attorney with Ross, Dixon and Masback who filed the suit in cooperation with the American Civil Liberties Union.

"Firefighters cannot say anything to the press that reflects negatively on the Fire Department" or they will be subject to administrative or disciplinary actions, Levin said. "And the Fire Department officials have virtually unlimited discretion in determining what is negative."

Beverly Burke, special counsel to the D.C. corporation counsel, said last night that the city had just received the court papers and had no comment.

At issue are two regulations in the Fire Department's order book, each of which is about five years old, and a 1985 Fire Department memorandum. One regulation prohibits cars with "obscene" or embarrassing decals or bumper stickers from parking on official lots; the other states that firefighters who bring the department's reputation into question by not paying their bills can be disciplined.

The memorandum prohibits officers and firefighters from talking to the media while on duty without written permission.

The District rescinded a similar D.C. personnel regulation in 1976 after a D.C. Department of Corrections employe and a firefighter filed suit to overturn it. Despite that action, Parker declared the provisions unconstitutional, stating at the time that it was his intention to prevent the city from implementing similar regulations.