Keep an eye on the American Federation of Government Employees lawsuit (pending in U.S. District Court here) challenging a portion of the federal pay act.

Under the current federal pay law the president can recommend a smaller increase for white collar government workers, even if pay data collected by his agents indicates that U.S. workers are due a much larger catch-up-with-industry raise. Unless either the Senate or the House veto the president's alternative plan it goes into effect automatically. AFGE says that is unconstitutional.

Results of the government's 1983 survey of selected private-sector wage levels will be released this month. The survey is expected to show that white collar civil servants--including more than 350,000 in the Washington/Baltimore area--are due an October increase of about 22 percent.

President Reagan has already said he will not recommend any pay increase this year. Senate and House budget conferees have approved a 4 percent raise that would be effective in January 1984.

AFGE's lawsuit is also asking for retroactive pay raises for government workers going back to 1979.

In that year, the government survey said federal employes were due a 13.5 percent raise, although they got only 7 percent. In 1980, the so-called comparability pay raise was supposed to be 13.5 percent, but President Carter authorized instead a 9.1 percent raise.

In 1981, the raise was supposed to be 15.1 percent, but the actual increase was 4.8 percent. Last year's pay raise was 4 percent although government data showed feds lagging an average 18.5 percent behind industry.

If the government was forced to make up the difference in pay raises denied feds for those years the retroactive payout could be $20 billion, or more.

Presidents Carter and Reagan have both argued that the comparability pay figures (arrived at by using data collected by government workers) are too high. They say the actual raise due U.S. workers would be much lower if the survey were broadened to take in rates paid state and local government employes, and a bigger cross-section of the private work force.