Attorneys for pretrial inmates at the D.C. Jail asked a U.S. District Court judge yesterday to order Mayor Marion Barry to show why he should not be held in contempt for violating part of a court order governing jail conditions and setting an inmate population ceiling at the facility.

In asking Judge William B. Bryant for a "prompt hearing" on the matter, the attorneys declared in court papers that Barry violated the section of Bryant's order governing jail operations under which Barry agreed to "fully support" the pending Prison Overcrowding Emergency Powers Act and "personally lobby" the D.C. City Council for its passage.

The bill, which was incorporated into Bryant's August 1985 order on the jail and is now before the council's Judiciary Committee, would authorize the mayor to take emergency measures in the event of an overcrowding crisis, including advancing inmate parole dates by 90 days.

The attorneys cited a May 7 letter from Barry to Judiciary Committee chairman Wilhelmina Rolark (D-Ward 8), in which the mayor asked her "to consider deleting or modifying" a section of the bill that would require new prison facilities built by the city to consist of single cells or rooms.

According to the court papers, "The mayor's letter is a direct attack on the very purpose of the bill, which is to provide humane conditions for prisoners, and strongly suggests a deliberate attempt to retract the commitment he previously made."

The bill now "precludes the District from artificially 'increasing' its capacity by building inappropriate dormitory housing into which increasing numbers of residents can be crowded, as has been done at the Occoquan facilities and the halfway houses," the papers state.

J. Patrick Hickey, one of the attorneys who filed the contempt request, said that "if the mayor's support for the bill was as bona fide as he said it was going to be, then he's been remarkably unsuccessful" in helping to get it passed. "He made a promise to support it -- not support it and then say, hey, by the way, why don't you cut the guts out of it."

Ed Koren, an attorney with the American Civil Liberties Union's National Prison Project, which represents sentenced inmates at the jail but took no part in yesterday's contempt motion, said, "We think it's perfectly appropriate that the mayor be held in contempt. It's outrageous that he's going back on his word. Apparently [the city's] signature doesn't mean very much."

Koren said the District "has ignored all provisions in the order expect the one on population, and the only way they have stayed under the cap is to crowd the only other facility [Occoquan] not under court order. They're not only looking for further contempt, they're looking for further litigation at Occoquan. They're really asking for it."

City Administrator Thomas Downs said last night that he was "disappointed that a misunderstanding or misconstruing of [Judge Bryant's order] would lead to a request of a contempt citation. It flies in the face of the extraordinary efforts the mayor has made in meeting every provision of that stipulation."

He said Barry fully supports the emergency powers act and has lobbied the council for its passage, but that the single-cell provision "is not an essential part of the . . . act itself."

Calling the contempt motion "posturing," Downs added, "I think throughout this, they [attorneys for inmates at the jail] have been more interested in celebrating rather than solving the problem."

Another contempt action pending before Bryant asks the judge to hold the city in contempt and to be fined for violating the 1,694-inmate ceiling at the jail last December and then attempting to cover up the violation.