DON'T BE MISLED by all the whining of Mayor Barry and other top District officials about unfair pressures from Attorney General Meese to take responsibility for prison crowding. It's high time the federal government put the squeeze on city politicians to decide once and for all exactly where they will build a new facility in the District, what kind it will be and when it will be ready. That is the useful message behind the Justice Department's announced refusal to accept any more city inmates in the federal prison system, effective today. Without this pressure, District officials might just keep on playing hot-potato games with the prison issue. But federal money and land are theirs to use for a new prison, and until they summon the political courage to pick a site and build, r. Barry has no beef coming.

True, the federal cutoff does cause serious difficulties for officials in the District. In recent months the city has been receiving about 100 newly sentenced prisoners a week. Since late August, the federal government has taken on more than 1,500 inmates as part of an agreement in a 14-year court battle between the city and attorneys for inmates who had claimed that conditions in the D.C. Jail violated the constitutional protections of suspects and convicts.

U.S. District Judge William B. Bryant threatened to hold the city in contempt and to stop it from placing any more inmates in the jail unless the jail population was reduced. He also said that if the city violated the agreement or if the population in the jail rose above 1,694, he would issue a contempt order and ban any increase in the jail population.

Mayor Barry came ever so slowly to a shaky conclusion that a new prison should be built -- but then not very courageously dumped the issue in the hands of a commission appointed by the D.C. Council. Now, six months later, a majority of this commission is still talking about alternatives to prison instead of what to build where. City officials have been fiddling with plans to stuff some modular buildings on the Lorton grounds.

Enough. Time's up. Mayor Barry should act like a mayor and make a decision. Then, if it's a firm commitment, Mr. Meese should ease up on the federal cutoff, pending completion of adequate facilities.