IT'S BEEN MORE than 200 days since this city has had a regular budget. The holdup is mainly due to Rep. William Natcher's total support for the city's request for money to build a convention center downtown, and Sen. Patrick Leahy's flat opposition to it. The disagreement between these chairmen of the House and Senate Appropriations subcommittees on the District has meant tht there has been almost no discussion of the city's 1978 budget request since October of last year, even though Rep. Natcher (D-Ky.) has been holding hearings on the city's 1979 budget for the past several weeks and Sen. Leahy (D-Vt.) will most likely follow suit next month.

Now, an honest difference of opinion between these two men is understandable, as long as both sides are making a good-faith effort to resolve the differences. But that, it increasingly appears, is not the case her. Mr. Natcher apparently feels himself duty bound to support the city's position until city officials offer to change it, which is reasonable enough. Mr. Leahy says he won't budge unil he gets an indication that the local business community is ready to put up some significant amount of private financing - anywhere from 15 to 40 percent. And that's also fair enough - or it would be if the business community refused even to talk about the possibility of a new appraoach. But that, we are reliably told, is not the case.

Quiet as it's been kept, Mr. Leahy has been approached for a meeting by representatives of the business community. More than a month ago, the presidents of the D.C. Bankers Association, the Metropolitan Washington Board of Trade, the Washington Area Contion and Visitors Association, the Hotel Association of Washington and the D.C. Chamber of Commerce tried to set a date to meet with the senator. On three separate occasions, Mr. Leahy's staff informed the group that the senator was not available - that the Panama Canal debate and his other duties just didn't affford him the time. On March 9, the group sent a telegram to Mr. Leahy, again requesting a meeting to "consider an alternative which would involve greater private-sector investment and a reduction in the long-term public cost of this facility." On March 10, the businessmen got this reply: "I am, of course, open to suggestions to resolve the D.C. budget impasse. However, I strongly feel such suggestions should come directly from the city or the House committee. Upon receipt of a written proposal from the city or the House, a meeting of all interested parties can be arranged. Sincerely, Patrick J. Leahy."

Given that invitation, you might well wonder why the city government has not responded with a proposal to Mr. Leahy. As far as we can tell, Mayor Washington is clinging to his forlorn and familiar hope that the Congress will somehow come to an agreement all on its own. For its part, the local business community has not gone beyond its suggestion that a portion of both the surtax on local businesses and the room tax on hotels be set aside for the center - an estimated $16 million over the next three years. The business leaders apparently have nothing to add (at least out loud), though it's fair to say that city officials haven't asked them to come up with anything else.

So there we are. No one will meet to discuss the center. no one seems especially concerned that a good portion of the money that the city cannot spend until it gets an approved budget is local tax revenue, paid by the residents of this city. No one appears to be much disturbed that the District may not get about 4,000 new jobs that are expected to result form building and running the center, in areas of highest local umemployment: semiskilled and service occupations.

The most promising way to break the deadlock, in our view, would be for Sen. Leahy to meet formally - or informally, for that matter - with city officials and discuss specific points for compromise. But even that initiative would offer no guarantee of a successful solution to this problem so long as everyone concerned remains reluctant to confront it constructively and responsibly.