The Fairfax County School Board caved in to political pressure and made a "farce and a mockery" of proper procedures in closing Fort Hunt High, an attorney for parents contesting that action argued yesterday.

But the School Board's attorney, Thomas J. Cawley, maintained that the decision was perfectly legal and came "after the most critical analysis and after every opportunity for the public to be heard."

Yesterday's closing arguments ended 2 1/2 days of testimony before Fairfax County Circuit Court Judge Richard J. Jamborsky in a case that each side estimates will cost it thousands of dollars. The lawyers representing Fort Hunt parents are donating their time, and the community is raising money for legal expenses. The School Board costs come from its budget.

The board voted in March to convert Fort Hunt High School to an intermediate school and send its students next fall to Groveton High, which will be renamed West Potomac High.

The board acted because enrollment is declining in the eastern part of the county and school space there underused.

As its last witness, the School Board called Paul Douglas, the Groveton principal who will continue in that job at West Potomac. Although the plaintiffs contend that the new school will be overcrowded, he testified it has room for all the nearly 2,400 students projected to attend.

Douglas said there will be fewer large classes at West Potomac than at Fort Hunt and Groveton combined, and the school will offer students courses not on the schedule at Fort Hunt or Groveton.

The plaintiffs contend that the School Board should have considered closing nearby Edison High School, but did not because of pressure from Sandra L. Duckworth, who then represented the Fort Hunt area on the County Board of Supervisors. Trying to establish a motive, they offered testimony yesterday that Duckworth lost the Fort Hunt precincts and won in Groveton and Edison in the 1979 and 1983 elections.

In agreeing to take Edison off the list of schools for possible closing, then-Superintendent William J. Burkholder "was surrendering the independent decision-making authority of the School Board and the school system," attorney Daniel Burke said in his closing argument for the parents.

That action had the "effect of turning the whole public hearing process into a farce and a mockery," he said. "Whatever merit the decision might have . . . it was considered improperly."

The plaintiffs cannot challenge the School Board's decision itself, but only whether it was arrived at in an arbitrary and capricious manner.

Cawley argued that the plaintiffs are trying to "inflate the importance of Edison" because the "decision of the School Board itself is so meritorious."

Edison High is in a growing neighborhood and includes a vocational center for the entire area, so Burkholder made a logical decision to urge against closing it, Cawley said.

If citizens had alternative proposals, "there was nothing to prevent them from making that argument to the board again and again and again," Cawley said.

Burke, however, said the School Board stacked the deck against Fort Hunt by taking Edison off the list of possible closings. He compared the situation to his own decision never to eat liver at home. His wife might put it on his plate, "but I don't give it good faith consideration," he said.

Judge Jamborsky did not indicate when he will rule in the case.