SELDOM HAS a groundbreaking financial plan, such as the building of a major league baseball park, traveled so far and so fast with so little public discussion. But D.C. Council Chairman Linda W. Cropp's ballpark financing plans -- first, constructing a new sports facility on the grounds of Robert F. Kennedy Memorial Stadium with public money and, second, building a stadium on a South Capitol Street site with private investors paying for the bulk of the project -- may set some kind of local high-water mark for doing the public's business out of public view. In the space of only a few days, Mrs. Cropp has unveiled two gargantuan stadium building plans based on private discussions with some of her council colleagues and private interests. The only parties left out of the picture are District taxpayers, who, when it's all said and done, will be expected to pay a large portion of the freight regardless of whether the mayor's plan or one of Mrs. Cropp's proposals survives. This is no way to conduct the public's business.

It certainly is the public's business whether the city will have to shell out $150 million for land acquisition and related infrastructure development, as envisioned in Mrs. Cropp's private financing plan. But what does the public really know? We know that Mrs. Cropp met privately with two business owners and their lawyer, who offered to pay two-thirds of the cost in exchange for exclusive rights to build the stadium in a tax-shelter scheme that benefits private investors. We know that Mrs. Cropp met behind closed doors with her council colleagues to discuss and weigh support for the mayor's public financing proposal and her alternative. We also know that those actions, led by Mrs. Cropp, are contrary to the public interest.

One may agree or disagree with the proposal Mayor Anthony A. Williams sponsored, but he did put his proposal before the public for debate. The same rule should apply to Mrs. Cropp and other council members. The idea of gathering behind closed doors without public notice of either the meeting or the agenda is contrary to open and good government. The practice is especially odious when decisions that are reached -- however informally -- involve public policy and the city's treasury.

The mayor is right to be outraged that Mrs. Cropp would hold private discussions with the council on an issue as important as the building of a major league ballpark. Mrs. Cropp's council colleagues ought to be equally embarrassed and annoyed by the practice of conducting business with the public locked out. Stadium plans are the public's business. The council should insist that all future discussions of a baseball stadium package be conducted in public view and with due notice to all concerned.