As Montgomery County school officials figure it, there are perhaps 2,000 students - the children of ambassadors, of foreign government workers, or of employes of international organizations - whose education is effectively subsidized by the taxpayers of the county and the state.

With this question in mind, the Montgomery County Board of Education was scheduled to decide last night whether to send tuition bills to these same parents, who often are exempted from paying the state and local taxes that support the schools.

A majority of board members already have expressed support for this plan, which has been under consideration on and off for several years.

The board has been under mounting pressure to deal with the question in this election season, however, since the county taxpayers', league, exercising its newfound political strength, has made the presence of diplomats' children in county schools a prime exhibit in its catalogue of government waste.

The taxpayers league, which is strongly advocating passage of a ballot referendum to slash the county's property tax rate, has estimated that the school system could have $15 million by approving the proposal. School officials, however, estimate the potential savings at $3 million.

The tuition charges for students whose parents pay neither property taxes nor state income taxes, would be $2,258 for students in grades one through six; $2,419 for students in junior high school and high school; and $5,409 for handicapped students in special education classes.

Under the proposal, the school system also would send proprated tuition bills to parents who paid some, but not all of the taxes that support their child's education.

"Taxpayer equity needs to be addressed," said school board member Blair Ewing last Thursday, when the school board decided to bring the question to a vote this week. "Montgomery County taxpayers are paying for the education of kids whose parents are not paying taxes."

Earlier this year, the State Department advised both school system officials and officers of the taxpayers' league that to charge diplomats tution for the education of their children in public schools could provoke a lawsuit.

Horace Shamwell Jr., the State Department's deputy assistant legal advisor, wrote the taxpayers league in March explaining that the State Department was "aware of no treaty provision or general principle of international law which would preclude this action" (the sending of tuition bills.

However, Shanwell added that, under international agreements, diplomats and their staffs are exempted from paying certain taxes. To force a diplomat to pay tuition bills in lieu of these taxes may be illegal, Shanwell wrote.

Another State Department official, Victor Vilatlana, said in an interview yesterday that he imagines diplomats or their staffs will "scream bloody murder or at least complain to the State Department. The obvious recourse is for diplomats to file a lawsuit and ask the State Department to file an amicus brief with the court," he said.

A number of embassy and foreign government employes contacted yesterday expressed disapproval of the measure, saying that their countries do not charge American diplomats or employes tuition for the public school education of American children.

"It seems unfair to me," said John Kay, an international organization representative whose son attends Bethesda-Chevy Chase High School. "The school board is trying to exercise taxing powers which it hasn't really got."

I doubt I would put my son in private school because he has been there for a while but I think a lot of other people may."

Kay said the measure would particularly hurt some staff members and servants of embassies and international organizations who are not well paid.

Most embassies provide diplomats and their staffs an educational allowance that would defray part of the tuition costs. Spokesman from the embassies of Australia and Belgium would not reveal the amount of their educational allowances, but a spokesman from the British embassy said the maximum would be two-thirds of tuition cost proposed by Montgomery.

The Montgomery County measure would affect holders of "A" and "G" visas - the former issued to diplomatic personnel, the latter to employes of organizations like the World Bank.

Under the measure immigrants, refugees and foreign exchange students would remain exempt from tuition costs, even though they are not legal residents of the county.

Charles G. Stine, director of the school's Department of Financial Services, said the county's 2,852 immigrant students and 436 students who are refugees would be exempt from tuition costs because they intend to becaome residents of the county and because their parents pay rent or property taxes.

Foreign exchange students would remain exempt from tuition costs because they are taking the place of a student whose parents pay state, U.S. and property taxes, he said.

School spokesman from Washington metropolitan area jurisdictions said they did not have a measure requiring diplomats and their staffs to pay tuition for their children's education and did not expect to pass one in the near future.

In addition to the foreign students who attend county schools, there are 150 nonresident students now attending county schools. Most of these students live in the District of Columbia and commute and their tuition amounts to a total of $300,000.