Neal Potter, retiring as president of the Metropolitan Washington Council of Governments (COG), called last night for area political leaders to intensify efforts to obtain local gasoline taxes earmarked to pay for Metro's bus and subway operations.

Potter, a Montgomery County Council member, told COG members, "I believe we must find an acceptable source of funding for the debt service (on Metro bonds) and operating subsidy of the system." His remarks were perpared for delivery at COG's annual meeting last night at the Shoreham-Americans.

"There is great reluctance to talk about taxes, especially in an election year," Potter said. Nonetheless, he said, "the proposal for a gasoline tax has come to be almost universally agreed upon."

Potter pointed to efforts in both surburban Virginia and Maryland legislative delegetions to seek state approval for local gasoline taxes.

The rising costs of Metro, while representing no more than 4 per cent of the operating budgets of most area jurisidictions, have nonetheless created enormous pressure to remove the burden of Metro from property taxes.

The Metro board itself has suggested that some kind of regional tax is essential to insure the financial integrity of the system. Such a tax would have to be adopted separately by Maryland, Virginia and the District of Columbia.

The need for an assured funding source is increasing every day. Recent projections for the Metro operating deficit have pleased it as high regionwide as $301.6 million annually in 1990 - when the full Metro system presumably will be in operation. That figure is stated in inflated dollars and assumes that Metro's fare would increase at about half the rate of inflation.

If Metro fares increased along with the inflation rate, according to the recent report, the nnual deficit in 1990 would be trimmed to $90.7 million.

Potter also pointed to recent census studies of the Washington area that have shown enormous deveploment in such outlying counties as Frederick, Charles and Prince William, while growth in the old core area has slowed.

He urged that counties such as Frederick be recruited for COG membership so that common problems - such as sewage treatment capacity, water supply and transportation - can be solved jointly. "We must tackle the problems together," Potter said, "or they will soon get out of hand."