The Education Department's Office of Elementary and Secondary Education, whose title mocks President Reagan's determination to get the feds out of the classroom, is on the verge of a major reorganization that would, in effect, get the middle managers and good number of program analysts out of that corner of the department.

The proposal has been viewed with suspicion at best and outrage at worst by some of the department's Democratic supporters in Congress as well as by the labor, women's and minority groups who note that many of the office's programs were designed to benefit the disadvantaged. Among the offices affected are those that administer anti-discrimination and remedial education programs.

Critics say that years of program expertise and commitment would be sacrificed in the shuffle proposed by Lawrence F. Davenport, assistant secretary for elementary and secondary education. Davenport, however, says the same amount of money would be going to schools for the same purposes. All that would be lost in reducing the staffing levels by 83 slots, 23 percent, would be a superfluous level of managers, he said.

"These are mainly supervisory personnel," Davenport said yesterday. "We don't need all these lawyers . . . . When we're going out around the country and talking about quality and efficiency in the schools, the first place you've got to begin is in your own house."

Davenport also expressed annoyance at the idea that reducing the staff, consolidating some of the offices and downgrading both offices and personnel would be interpreted as a lack of commitment to the programs. "What I have trouble with is people saying there is something wrong with efficiency," he said.

"We're providing money to the states and the local education agencies. This will be continuing. Not one single function is going to be discontinued.

Critics, including the president of the department's employes' union, Maryann Nelson, ask how that is possible. Her local is among those leading the charge against the proposed reorgnization and the accompanying reductions-in-force that are likely to result in pink slips for more than 120 employes throughout the department, most of them in the OESE.

The office administering vocational and adult education programs also would lose personnel if the department's manpower drops, as scheduled, from 5,450 to 5,253 by Sept. 30. Some of the reduction is supposed to be achieved through attrition and early retirements.

"We have no problem with the concept of reorganization because we see there are problems in the distribution of the work," Nelson said yesterday. "There is a top-heaviness in some of the programs . . . . We have questions concerning their analysis. These reorganization proposals are completely irrational. They have not been justified. If there's a discrepancy in the workload, why not shift people instead of laying them off ?"

Monday the union gained important allies, Sen. Christopher J. Dodd (D-Conn.) and Rep. George Miller (D-Calif.).

In a letter to Reagan seeking postponement of the plan, the two lawmakers said that it would "contribute to the already unacceptable morale problem, while placing in jeopardy the integrity of effective education programs and the entire department."

The legislators also accused Reagan, whose promise to abolish the department has been abandoned, of trying to do administratively what he did not accomplish legislatively.