IT WAS A SIMPLE but important bill, rightly deemed in the public interest by Maryland legislators from both parties, passed resoundingly by both houses. The measure would have improved significantly the public's ability to monitor and enforce the state's Open Meetings Act, which requires public bodies to conduct their business in public. Yet with a lame excuse, Gov. Robert L. Ehrlich Jr. (R) has vetoed the bill.

The corrective measure stemmed from a case brought before the Howard County Circuit Court in which a plaintiff alleged that the county school board had violated the state law; the judge dismissed the case, saying that the plaintiff had failed to prove harm, in the sense of being denied a right. The case is being appealed, but the open-meetings legislation was intended to ensure that anybody could take legal action to enforce the law.

Del. Elizabeth Bobo (D-Howard) and Sen. Brian E. Frosh (D-Montgomery), the bill's chief sponsors, noted that any member of the public has an interest in public business being conducted in the open and should not have to demonstrate a direct pecuniary interest to bring the issue to court.

News media organizations, including The Post, supported passage of the legis- lation, which was clearly aimed at preventing closed-door government. But in vetoing the measure, Mr. Ehrlich said it could result in an increase in litigation and accompanying legal costs for government bodies. That's a flimsy way to the skirt the issue. The way to minimize litigation is to maximize the sunshine on public business. The legislature had it right and should organize for an override.