On a Sunday evening late last month, about 60 Northwest Washington community activists, tenants and D.C. City Council members made their way through the spacious marble columned lobby of a Columbia Road apartment building to a second-floor apartment, where they sipped white wine from plastic glasses, and discussed how to fight to save the charm of their Adams-Morgan neighborhood.

At the same time, the Hotel Association of Washington, D.C., had spent an estimated $75,000 over the past year on consultants and attorneys to help in their battle to get flexible hotel zoning laws in the city."In the 13 years I've been here," said Leonard Hickman, the association's executive vice president, "never has this association devoted so much time and money to one project."

Today groups will turn out in full force for a city zoning commission meeting that will determine who wins their battle over proposed massive changes in the city's hotel developement regulations.

It is the flight that has flooded the commission with more letters of opinion than any other zoning issue in the past few years, according to one staff member. Hearing in the case have generated more than 500 exhibits for commissioners to consider.

Much of the citizens' anger has been directed at D.C. Mayor Marion Barry. The planning department last month recommended that the zoning commission approve major changes in hotel zoning that among other things, would allow the Washington Hilton, at 1919 Connecticut Ave. NW, to expand, demolishing at least three Columbia Road apartment buildings that house more than 250 people, many of them elderly persons on fixed incomes.

Tenants in the three building -- the Wyoming at 2022 Columbia Rd., the Schuyler Arms at 1954 Columbia Rd., and the Oakland at 2006 Columbia Rd. -- say they've been betrayed by the major, who promised at a rally last summer to stand by them in their fight to block the expansion of the Hilton.

The tenants and their Advisory Neighborhood Commission supporters have protested, picketed and blanketed their buildings with fliers telling residents to write the major -- and what to say. Neil MacCracken, one of the organizers who lives at the Wyoming, estimates that she and another tentant have each spent more than $500 on telegrams and photocopying letters.

Last Saturday, an Adams-Morgan rally drew more than 400 people to protest the mayor's stance on the hotel expansion. And last night, about 70 demonstrtors picketed outside the Hilton, while inside, the mayor was having cocktails at a reception sponsored by the Boys Scouts of America.

The tentant groups have begun working toward hiring a zoning attorney to represent them in case court battles are necessary and trying to raise funds. Before the landlord who owns all three buildings can sell them to the Hilton, he must offer to sell the buildings to the tenents. MacCracken said they want to be prepared.

If the planning department recommendations are approved hotels located in residential areas on major arterial streets could expand onto adjoining land. Planning staff members said yesterday that three of the 24 hotels in the city's residential neighborhoods could expand under that definition -- the Hilton, the Fairfax Hotel on Massachussetts Avenue and Highland Towers across the street from the Hilton on Connecticut Avenue.