The Maryland General Assembly today received a new weapon in its continuing battle with Gov. Harry Hughes over prison policy -- a $110,000 consultant's report saying that almost one-third of the inmates assigned to prerelease centers around the state belong in more secure settings.

The study, commissioned by the 1980 General Assembly and presented to the Senate Budget and Taxation committee today, fueled the legislators' standing argument against Hughes and Gordon Kamka, his controversial secretary of Public Safety and Corrections, who are steering the state toward an emphasis on building community-based rather than maximum-security facilities.

The senators and several members ofthe House of Delegates, who will hear the report next month, predicted that it will make the prisons issue one of the most emotional of the 1981 session.

A Hughes aide reluctantly said the same: "Prisons usually tie with abortions for the emotional issue-of-the-year award. The problem is, of course, that this is not the kind of issue you can solve overnight."

In setting corrections policy, the Hughes administration has had to come to terms with two major factors -- a federal court order to reduce overcrowding in the state's prisons and political pressure from the legislature to build maximum-security facilities that Kamka and his aides oppose.

The legislature's consultant, Correctional Services Group of Kansas City, said a substantial number of the 7,700 state prisoners in Maryland are not housed securely enough, including about 500 of the 1,800 who are assigned to minimum-security centers, from which almost all of the escapes occur.

It is those centers, and the types of prisoners assigned to them, that have sparked the most political controversy in recent months. Last October, an Anne Arundel County grand jury reported that more than 70 percent of the prisoners assigned to minimum-security centers in the county were violent offenders, prompting calls by local officials -- most prominently, County Executive Robert Pascal -- for a change in state corrections policies.

According to the consultant's report, Maryland's system of classifying prisoners needs major changes that would require a "substantial increase" in the size of the corrections staff -- a recommendation that is not likely to be popular in this year of Maryland's fiscal squeeze. While many of the state's inmates are not housed securely enough, at least one-fifth are now serving time in setting that are more secure than necessary, the report said.

The report blamed most of the disarray on the Hughes administration's effort to comply with the federal court order to ease overcrowding at the Maryland State Penitentiary in Baltimore, the only maximum-security prison in the system. Spurred by the court order, prison officials are pushing inmates too quickly into medium- and minimum-security settings, one of the report's authors, Bob Buchanan, told the hearing.

This remark prompted criticism from several of the senators, who said they did not need to spend $110,000 to discover that overcrowding has created problems for the prisoner-classification system.

"I think our cleaning person could have come up with that conclusion," said Sen. Julian L. Lapides (D-Baltimore), who represents the district where the penitentiary is located. "I think we all knew that."

Kamka, who sat in on the presentation of the consultant's report, said afterward that he does not feel he learned anything new from it.

The flurry of political cross-fire over the consultant's report came at the same time that the prison system faced another hurdle -- this one involving the federal court order to ease overcrowding. Starting today, the state parole board dramatically relaxed its parole requirements in response to a ruling last week by U.S. District Judge Alexander Harvey II, saying that the board was not doing enough to address the overcrowding.