More than 90 percent of federal workers responding to a newspaper questionnaire said they will vote against President Carter and any other politician who extends social security coverage to the bureaucracy, or back proposals to cut back the number of inflation raises retirees get.

In the 5 days from Monday until Friday more than 14,000 letters, cards and "ballots" clipped from The Washington Post were received and tallied at the Post. They came from people who identified themselves as civil servants, family members or federal retirees. They were in response to a request published in last Sunday's Federal Diary column in the Metro section of this newspaper.

(Post officials said the response represents the most mail the newspaper has even received on a single subject issue.)

Figures show 98.8 percent of the respondents oppose integration of the civil service staff retirement system with social security, and are against an Administration-backed bill that would limit federal and military retirees to a single annual inflation adjustment, instead of the cost-of-living raises they now get every six months. Just over 90 percent said they would vote against Carter or their member of Congress if either supports the pension changes.

Half of the responses came from individuals who said they are registered voters in Maryland. Just over 37 percent said they vote in Virginia and 7.9 percent said they are registered in the District of Columbia. Almost 5 percent came from people who said they are registered in other states -- primarily Pennsylvania, North Carolina and West Virginia. Toward the end of the week ballots began coming in from as far away as New York, Florida and Utah. Telephone calls -- from Texas and California -- were received, but not counted in the final tally.

The mail ballot is not a scientific poll. It was targeted to Washington Post readers, and readers of a particular column. Respondents did not represent the careful cross-section pollsters seek when making a survey.

An expert pollster noted, in addition, the questions asked were for yes or no answers and did not leave room for "undecided" or "don't know" responses. o(Nevertheless, thousands of individuals wrote in comments on the ballots. Only a handful said they did not consider the retirement issue important enough to sway their vote).

The issues are, however, of major concern to active duty federal and postal workers -- there are 370,000 here -- and to retired federal civilians and military personnel.

Congress is considering recommendations of a blue ribbon task force it created to determine how best to bring nearly 6 million federal, state and local government workers under social security. Federal and postal employes now have their own staff retirement system. Many have, or will earn social security credits for work performed in private industry.

If the federal retirement system is "integrated" with social security, workers would pay into both funds. Benefits they receive at retirement would be prorated between social security and the civil service system. Many federal employes fear the linkup of the two very different systems would erode benefits, or force them to work longer to get the same annuities they are now due. Federal, postal and retiree groups have raised a $3 million war chest to fight mandatory social security, and the proposal to cut back the number of cost-of-living raises.

The Carter Administration has endorsed recommendations of the Senate and House Budget Committees to eliminate one of the two cost of living raises retirees now get each March and September. If approved, retirees would get a single cost of living raise each year, in March. Persons under social security get one COL raise a year, in July.

Last week the Retirement Federation of Civil Service Employes released results of a poll it made of nearly 12,000 workers at the Norfolk Naval Shipyard. Fifty-four percent responded, and 99 percent opposed mandatory social security coverage. Sixty-six percent said they would quit government if transferred to a combined civil service social security pension system.

Written comments to the Post survey varied. One worker favored retaining the independent civil service system for those already in it, but extending social security to newly hired employes. He added: "I abhor single issue politics and find this particularly too small an issue upon which to choose the leadership of the nation."

The overwhelmingly majority, however, said they would vote against Carter or any other elected official who tries to change the retirement system, or reduce inflation catchup raises for retirees.