In nearly fours years, since March 1977, members of Congress, top-ranking federal executives and judges have received a single pay increase -- 5.5 percent in October 1979.

Over a decade ago, in 1969, members of Congress were paid $42,500 a year. If that had risen in step with the consumer price index, according to a study by government personnel specialists, the nation's lawmakers would now be making $98,200 a year.

Federal officials point to numbers such as these as a defense of Congress's move to raise its own pay, and that of nearly 2,500 top-ranked personnel in the other two branches of government whose salaries the lawmakers have tied to their own.

The top salaries affected would be those at the level of vice president, speaker of the House and chief justice. They would increase from $79,125 to $92,400, the highest in government except for the president, according to congressional figures.

At the next level, Cabinet officers would jump from $69,630 to $81,300. Below that come members of Congress, assistant secretaries and appeals court judges, who would rise from $60,662 to $70,900. Federal district judges would go from $57,500 to $67,100.

The lasrgest group that could be affected by congressional pay raises includes some 34,000 senior bureaucrats (GS15 and above) charged with running executive branch agencies. Federal personel officials have long argued in favor of a raise because of what they call pay "compression" at the top.

While the million-plus white collar career civil service workforce has received steady pay increases -- the latest a 9.1 percent rise in October -- salaries for their bosses at the top have been frozen at $50,112.50. Senior executives on at least five different levels of responsibility now earn the same pay, one official noted.

Unfrozen senior bureaucrats would get varying percentage increases up to 16.5 percent, depending on how much their pay has been compressed, according to congressional staff estimates. The actual amounts may vary from $2,000 to $8,000.

According to congressional promotors of the pay raise, notably Sen. Ted Stevens (R-Alaska), as well as federal personnel officials, the freeze has made it difficult for the government to compete with industry for talent, is causing vacancies in some key posts and is creating morale problems among top executives.

Opponents of the pay raise such as Sen. James Sarrer (D-Tenn.) contend that the Congress, seen by many as a contributor to inflation, should not be able to insulate itself from inflation's effects.

In addition, they argue that the prestige of many Washington jobs makes them easy to fill even at current salary levels -- how many people would turn down secretary of state because it didn't pay enough? -- and that service at high levels of government often paves the way to high-paying jobs in the private sector.

By law, congressional and other top federal salaries are supposed to increase automatically every year in step with the raises given to the general civil service workforce, Gary R. Nelson of the Office of Personnel Management explained. "But [in recent years] Congress has consistently used the appropriations mechanism to deny funds for these raises. The statutory rates went up 9.1 percent on Oct. 1 -- but they just weren't payable."

Congressional pay has for at least 10 years been informally linked to Executive Level II pay scales, the level below Cabinet rank, Nelson said.

Congressional pay remained at $42,500 from 1969 to 1977, when it rose to $57,500. The only raise since then was the 5.5 percent in 1979, according to congressional figures.

The pay of lower-ranking career-civil servants during the years since 1977 has been raised, each year respectively, by 7.5 percent, 5.5 percent, 7.5 percent and this year 9.1 percent, according to OPM.

The pay of the president, currently $200,000 is set separately by statute.