Gov. Michael S. Dukakis, who is fond of referring to Massachusetts as "the nation's preeminent education state," may find his education agenda a tough sell with fiscal critics this year, State House insiders said yesterday.

Some legislators and staff on the Committee on Education said that although outlays have been relatively safe from budget cuts in the past, this year may be different.

"In this case, [the education budget] is highly unsafe," said Sen. Michael Barrett '70 (D-Cambridge). "I think everything is vulnerable."

Dukakis last month proposed a $1.8 billion spending plan for the state Department of Education, which oversees primary and secondary schooling. The proposed spending increase of 2.3 percent for fiscal year 1990 comes in the midst of the state's ongoing fiscal crisis.

Dukakis' overall spending plan of $13.4 billion has been criticized by legislative leaders, who have asked the governor to submit a smaller budget in light of the state's current $636 million deficit. million deficit.

The Dukakis FY '90 budget is contingent upon legislative approval of a two-year $735 million tax increase requested by the administration. Many legislators have called for further spending cuts rather than a tax hike.

John Howat, aide to Senate Education Committee Chair Salvatore R. Albano (D-Somerville), said that education's relative immunity from budget cuts in the past few years was in part a result of economic prosperity. "In the past five or six years, the Massachusetts economy was thriving. No area of the budget was really cut too much."

Howat also said that part of education's past immunity from cuts can be attributed to popular support. "In terms or what we've heard from constituents, nothing in education should be cut at all. Everybody likes education."

But in the current fiscal crisis, Howat said, popular support may not be enough to protect the education budget. "That support really doesn't mean that those line items are beyond scrutiny."

The proposed Department of Education budget, which is separate from the requested $791 million public higher education budget. calls for:

. A 14 percent increase in the Magnet School program, up to $6 million. "Magnet" schools in Boston and Worcester offer specialized programs of study designed to encourage students fleeing the public education system to enroll in inner city schools. Proponents claim that Magnet schools attract students from throughout a school district and help alleviate racial imbalance.

. A doubling of the funds for adult education services providing training in reading, writing and mathematics.

. $1.1 million in additional funding for the Metropolitan Council for Educational Opportunity (METCO) program, bringing the budget to $14.3 million. METCO, a program designed to combat segregation in education, pays for the transportation of Black Boston youths to suburban schools.

. A 20 percent decrease in grants to local schools for programs for gifted and talented students.

. A savings of $500,000 by discontinuing a program of emergency grants to local schools for students whose primary language is not English.