A plan to accelerate the parole eligibility of District prisoners who meet certain educational criteria could lead to "virtually unfettered discretion" in release of prisoners, D.C. Superior Court Judge Fred B. Ugast has charged in a strongly worded letter asking the City Council to delay consideration of the proposal.

Ugast, head of the felony trial division here, said a bill set for a final council vote Tuesday "would accomplish unilaterally a reduction of the minimum term of sentence without even coming back to the sentencing court." Ugast's three-page letter was hand-delivered Friday to Council Chairman David A. Clarke.

The bill, approved by the council two weeks ago on first reading, directs the mayor to establish a program that would allow a prisoner to be considered for parole at an earlier date than the minimum sentence provides if the prisoner has completed academic or vocational programs.

Under current law, only the sentencing judge may order the reduction of a prisoner's sentence before the initial parole eligibility date. The new proposal also would give the Parole Board that discretion.

The bill, also aimed at reducing crowding at District prison facilities, is one of several proposals in the Washington area to link educational programs with release dates. The underlying philosophy of these programs is that illiterate inmates are more likely to fail in finding work and likely to return to prison.

Ugast said, however, "By not placing any limits on the amount of time which the Parole Board may credit a prisoner for educational attainments, this bill virtually removes from the judiciary the capacity to sentence based upon predictable variables."

The bill has spurred an unusual amount of behind-the-scenes lobbying by Superior Court judges, who traditionally shun involvement in the political arena. A special session of the court's legislative committee was called to discuss opposition to the bill, and a draft of Ugast's letter was circulated last week among the court's 51 judges. Chief Judge H. Carl Moultrie I said last week the bill would "usurp the authority of the sentencing judge" and "undermine" a two-year study that is nearing completion by a special commission to make sentences more uniform.

Clarke called the jurists' concerns "premature" and criticized their "quick judgment." The bill, he said, merely directs the mayor to propose a formula by which prisoners could receive credit for completing educational programs. Before the program could go into effect, the public would be able to comment and, the council would have to give final approval.

"Certainly the judges, being circumspect people, ought not judge something before they see it," said Clarke, "All this bill calls for is the development of rules and regulations . . . . I hope the judges are not so quick in making judgments in the cases that come before them."

In his letter, Ugast stressed that he supported the bill's intent to provide incentives for prisoner rehabilitation, but he added that "in a single stroke, this bill would eviscerate much" of the study by the Sentencing Guidelines Commission. Ugast chairs the commission, and Clarke is a member.

Currently a prisoner is eligible for parole after serving one-third of a maximum prison sentence. Ugast noted, however, that laws exist allowing the Parole Board to recommend to a judge that a prisoner's sentence be reduced, making the current proposal "wholly unnecessary." Under the new bill, also opposed by the U.S. attorney's office, the Parole Board does not have to return to the sentencing judge.

Walter Ridley, chairman of the Parole Board, said the board was reluctant to discuss the intent of the bill, but he added, "Whatever decision we render will be based upon public safety."