Washington area government workers who shared in this month's 4.1 percent general federal pay increase would get an additional 8 percent locality adjustment under legislation expected to be introduced soon by Rep. Constance A. Morella (R-Md.).

On the Senate side, Sen. Barbara A. Mikulski (D-Md.) is expected to reintroduce her bill that would give the same 8 percent special raise to white-collar federal workers in Baltimore.

Neither plan is likely to become law. But they could push the Bush administration to recommend some kind of pay differential, probably less than 8 percent, for workers in the two cities. These workers make up about 15 percent of the total federal work force.

Using the new federal pay law, President Bush has announced special 8 percent raises for white-collar government employees in New York City, San Francisco and Los Angeles. Officials say those are the three areas where the federal government has the toughest time competing with the private sector.

More than 50,000 of the 360,000 federal workers here already are paid special rates, ranging from 2 percent to 30 percent above their normal grade level, because they are in jobs that are hard to fill. Nationwide, most of the special-raters are engineers, scientists and medical personnel. Locally, the bulk of the special rate recipients are clerical employees in Grades 2 through 7. Retirees to Meet

Al James Galato will speak at today's 1:30 p.m. meeting of the Georgetown chapter of the National Association of Retired Federal Employees. Galato recently took over as national vice president of NARFE. The meeting is at the Guy Mason Recreation Center. King Celebration

Jesse L. Jackson will be the keynote speaker at a special program Thursday at the Labor Department to honor the birthday of the Rev. Martin Luther King Jr. The 10 a.m. meeting is being sponsored by the department, the American Federation of Government Employees Union and Blacks in Government. Nice Boss

Because of the new federal pay law, the Advisory Committee on Federal Pay is due to go out of business on Jan. 25. It was set up to study federal and private pay rates and make recommendations -- free of politics and budget considerations -- to the president.

Martin L. Duggan, a former St. Louis newspaperman, is chairman of the advisory committee. He came to town billed as an anti-government type who would tell the Reagan White House that bureaucrats were overpaid and underworked. In fact, he was a strong advocate for higher federal pay, a position that cost him points at the White House. Several union leaders who worked with Duggan said he was a very gracious man in a frequently thankless assignment. So how nice is he?

In his final days in the chairmanship, Duggan is trying to find new jobs for the committee's two full-time staff members, who don't necessarily want to retire. Duggan has contacted potential employers praising the two career civil servants, Betty Woodward and Lucretia Dewey Tanner, and urging that they be kept in the work force.