Opponents of mandatory Social Security for federal workers think they have a good chance of persuading the House to kill or sidetrack the issue. It is due for a vote Wednesday.

Legislation requiring servants to go under Social Security beginning in 1982 cleared the House Ways and Means Committee be a lop-sided vote. Many members of Congress favor it, in part because it would hold down future Social Security tax increase if government workers are forced to contribute to the system.

However, there has been a shift in congressional thinking in the past few days. The House Post Office-Civil Service Committee voted 24-0 to keep government workers out of Social Security for now. The committee wants a detailed study before "universal coverage is extended to the federal work force.

Federal and postal union lobbyists have been working overtime explaining the dangers of a "nasty" move mandating universal coverage. They've been calling in political IOUs from friends on Captiol Hill. In addition House members have been swamped from calls from government employee constitutents, telling them to block the mandatory Social Security coverage plan.

Union leaders believe they've persuaded House Speaker Thomas P. O'Neil (D-Mass.) that this isn't the time to overlap Social Security with the much more generous federal retirement plan. Members of Congress, incidentally, are under a retirement system that is modeled on the government program, but one which provides better benefits quicker (at greater cost to members) than the regular civil service retirement program.

The strategy, for anti-Social Security coverage forces, is to win approval of amendments that would strike government workers from mandatory coverage. This in turn would require the House to vote a higher than anticipated Social Security tax increase for 1978.

Those amendments, by Rep. Joseph Fisher (D-Va.) and Gladys Spellman on the feasibility of putting federal and postal workers under social security. Fisher will offer the plan as a member of the Ways and Means Committee, which has jurisdictim over Social security and tax writing. Spellman belongs to the Post Office-Civil Service Committee which handles federal-postal matters.

Hispanic Recruiting Drive? The entire issue of the government's latest newsletter with recruiting tips for state and local governments is devoted to the nation's second largest minority group - persons of Spanish descent.

The federal publications tells recruiters to use Spanish-language radio stations to tell of job openings, and to spend more time in junior (two years) colleges.

TMeantime, the Civil Service Commission is preparing two publications aimed at recruiting high school age Hispanics for federal, state and local government jobs. They won't be available until January, but agencies in government and at the state level already are getting word to be more aggressive in seeking out persons of Mexican, Cuban, Puerto Pican, Central or South American descent.