One year from today, voters in this city will have completed the first full electoral cycle since being granted limited home-rule in 1974. Judging by the way things are shaping up for not only the mayoral election, but for seats on the City Council as well, this first milestone could well be marked by a political free-for-all, similar to that of four years ago.

Buried in the underbrush beneath the more publicized maneuvering over who will be the city's next mayor, it the fact that at least seven seats on the Council - including that of the chairman - will be up for grabs. Already the names of nearly two dozen Council hopefuls (including five incumbents) are beginning to float out.

There are those who had hoped that the 1974 election - the first for Council and mayor that had been held in more than a century - had marked both the first and last time when virtually anyone who had a name or a desire would run for city government. But now it seems it could happen all over again in 1978.

By the admission of some of its ranking members, the local Democratic Party organization - the D.C. Democratic State Committee - is still too young to prevent ambitious upstarts from getting into the race. Robert B. Washington Jr., the state committee chairman, says that he doesn't think the committee should make endorsements until after the primary elections, anyway (except in unusual circumstances).

Nearly three of every four voters in this city are registered Democrats, and winning the Democratic primary is frequently tantamount to getting elected. The hands-off party attitude plus other factors in next fall's elections seems to suggest that Campaign '78 could well become a laissez-faire sellers' market for D.C. politicians, despite the effort of Del. Walter E. Fauntroy and others to exert some kind of controls.

"For those who aren't involved in it, yeah, it will be fun," one City Council member up for reelection next year complained privately last week. "But when you're looking at your job security and your career, it's a different story."

For openers, at least two of the most coveted chairs on the Council are likely to be vacated. Chairman Sterling Tucker is expected to run for mayor, and atlarge Democrat Douglas Moore is already running as Tucker's heir un-apparent.

What will really make the race more interesting is if the Council's other at-large Democrat, Marion Barry, follows through with his announced intention to run for mayor and resigns as required by current city law. Depending on the time that Barry resigns from his Council seat, it is possible that both at-large positions now held by Democrats could be open at about the same time, but with different electoral qualifications for filling each.

Barry's seat would have to be filled via a one-shot, winner-take-all special election and would be up for grabs within four months of his time of departure. The other at-large seat now held by a Democrat, Moore's, would have to be filled in the regular fashion. Whatever Democrat managed to survive the Democratic primary, would then have to be one of the top two vote-getters in the general election.

City election law allows no more than two of the four at-large seats to be held by a single party. A third at-large seat, that of D.C. Statehood Party representive Hilda Mason, is also up next year. And if that's not enough, consider what would happen if other members of the Council whose terms are not due to expire until 1980 - like John Wilson and Arrington Dixon - decide to give up their ward seats and run for an at-large post or the job of chairman.

Another factor that is likely to affect the field of candidates in next year's Council race is the city's new civil service system, which is now in the final stages of preparation and is expected to become effective on Inauguration Day, 1979.

Tucker away in that bill are provisions that would raise by about $7,000 the salaries of the Council members - to a wholesome $35,000. Many in the city have complained in the past that the salaries are too low to attract some people more experienced in government and related fields onto the Council. But the higher salary could bring into the race a few people who might not otherwise be able to make the financial sacrifice demanded by the present salary, $28,000.

So far, the political maneuvering over the 1978 elections has been aimed at the mayor's job, with a little more attention being paid recently to the chairman's post when it became evident that the only announced candidate, Douglas Moore, had suddenly popped up as the man to beat - partially by a process of elimination.

Joseph B. Danzansky, the president of Giant Foods, insisted this week that mathematics is sometimes a different science when politics is involved. In 1974, Danzansky was the finance chairman for the election campaign of Mayor Walter E. Washington. Monday night, Danzansky was the chief sponsor for a $100 to $500-a-head fund-raiser at the National Democratic Club on Capitol Hill aimed at drumming up money for Del. Walter E. Fauntroy's 1978 campaign.

Fauntroy has already made it known publicly that he will not back Mayor Washington for reelection should the mayor seek another term. So if Danzansky is so gung-ho for Fauntroy, one and one must be two, and Danzansky must also have written off the mayor, right?

Not so, Danzansky said: "I will never give up on Walter Washington."