This is a tale of two cities. The first is New York, where, if things continue, there will soon be no jail space for corrupt city officials. The second is Washington, where there is a similar smell of corruption but a higher order of politician. The city is already out of jail space.

In New York, the finger is pointed at Mayor Ed Koch. Although supposedly personally honest, he is accused of tinkling away on the old 88s while his Democratic Party chieftains escorted municipal contractors up the stairs for illicit reasons. By turning the city over to the old politics, Koch made sure New York got the old corruption.

In Washington, we have a similar story. While the corruption is nothing compared with New York's (neither is the pastrami, for that matter), once again the personal style of the mayor is at question. We are talking, of course, of Mayor For Life Marion Barry. Like Koch, he is a self-proclaimed dandelion growing in an ever-widening junk yard.

Barry himself was under investigation by the U.S. Attorney's office here, and nothing came of it. His close friend and aide, Ivanhoe Donaldson, was convicted of corruption. His one-time Alcoholic Control Board Chairman, Robert C. Lewis, was similarly convicted of corruption and his deputy mayor for finance, Alphonse G. Hill, is under investigation for (yawn) corruption. It seem almost insignificant that the city's Public Works Director, John Touchstone, has taken two trips that were paid for by a firm that does business with the city.

But if Koch's mistake was to turn the city over to the old Democratic clubhouses, then Barry's was to set a personal example that suggests almost nothing could offend him. Right off the bat, for instance, the mayor accepted a 3.25 percent discount ($242 a month) on a mortgage from a bank that, like any other, stood to benefit from municipal decisions. The mayor later decided not to accept the discount, and, of course, denied that he had done anything wrong.

Not too long after that, it was revealed the mayor went to a party at a 14th Street NW strip joint called "This Is It." The owners of the club were, at the time, under grand jury investigation. No matter. Barry said he was only there as a guest and, besides, he was mayor of all the people. Oh.

The mayor had a different explanation as to why he occasionally dropped by Karen Johnson's place. She was the city employee who was convicted of selling and possessing cocain. The Post reported that Johnson had told her boyfriend that she sold cocaine to the mayor, but Barry said that's not why he went to see her. It was to talk and sip cognac. Oh again.

By now, Barry has taught Koch a thing or two. Where Koch is personally scrupulous but politically naive, Barry may be neither. Indeed, he represents the return of political patronage, exults in the almost affectionate title "Boss," and the business community contributes to his campaign as if he were a politician who rewards his friends and punishes his enemies.

To his credit, Koch is momentarily humble. He concedes he has done something wrong. No such admission emanates from the District Building. Not only does Barry apparently think his personal conduct is unrelated to his municipal scandals, but he is loath to punish subordinates when they publicly get out of line. When the Donaldson case revealed that a whole lot of people thought city contracts were the toys of the influential, Barry acted as if he only had a serious accounting problem on his hands. Not only did he not get instantly indignant, he waited weeks before he took action.

Even now, we have yet to see a requisite snit about Touchstone, the public works cirector. A city contractor, Datacom Systems Corp., picked up $1,720 worth of his and an aide's hotel and travel bills, but the mayor has yet publicly to read Touchstone the riot act about ethical conduct. Instead, Touchstone says he will return the money, and the mayor, as usual, simply proclaims his own innocence.

From time to time, Marion Barry complains that the U.S. attorney is out to get him and that he is personally scrupulous. Maybe on both counts. But he would be a lot more believable and the city would be a lot cleaner if he would, as Koch has done in New York, acknowledge that his personal and political style has a bearing on the conduct of others. It would be, to paraphrase the original "Tale of Two Cities" a far, far better thing than he has ever done before.