Nearly two dozen lawmakers - most of them from New Jersey, California and Illinois - paraded before a House defense panel to criticize plans to shut down or mothball military bases in their districts.

The congressional hearing Wednesday was the first on a proposal by a blue-ribbon commission to close 86 military installations in the United States and to "mothball" - or partially close - others.Nearly all of the 21 members of Congress appearing before a House Armed Services subcommittee challenged the commission's estimates of the costs and budget savings envisioned under the plan.

By their own calculations, or according to figures they obtained from the military, many lawmakers said the panel exaggerated the savings that could be expected and seriously underestimated the base shutdown costs.

In many cases, they said, it would cost more to close or scale back a base than to keep it open - primarily because of environmental cleanups and the expense of transfering operations to other installations.

They also said the commission failed to provide adequate data to justify its decision and stonewalled attempts by members of Congress to obtain more information.

The criticism also reflected the parochial objections Congress intended to avoid when it created the commission to recommend a package of base closings that lawmakers would have to accept or reject in entirety.

The commission recommended in December that 34 major domestic military installations and 52 smaller ones be shut down by 1995 and that others be scaled back or "realigned."

The commission estimated that its plan, approved in January by Defense Secretary Frank Carlucci, eventually would save the government nearly $700 million a year.

By law, the closings can be initiated by the Pentagon between next January and September 1991 unless Congress votes to reject the whole plan.

Among the recommendations that drew the most fire was a decision to place Fort Dix in New Jersey on semi-active status, to close the Presidio Army base in San Francisco and to shut Chanute Air Force Base in Illinois.

Boxer and Nancy Pelosi, D-Calif., said closing the base would end up costing the government $26 million more each year than keeping it open.

Eight members of the New Jersey congressional delegation, Democratic Sens. Bill Bradley and Frank Lautenberg, criticized the decision to mothball Fort Dix, one of the Army's primary basic training centers.

Lautenberg said the government had invested $160 million to upgrade Fort Dix since 1980 and argued that by placing the base on semi-active status, "we must spend $95 million more up front to save only $86 million more over the long term."

Rep. Jim Courter, R-N.J., said the commission's report "reads like a last minute term-paper," and Bradley said, "The commission issued a report that failed to support its conclusions."