County Executive Maggie Brooks' plan to bridge a $50 million budget gap will face a legal challenge.

In a 20-minute meeting Wednesday night, suburban school districts in Monroe unanimously voted to sue the county, saying the plan is illegal. The districts stand to lose about $29 million because of the executive's FAIR Plan, which calls for a 50 percent cut in the amount of sales tax revenue given to each district.

Monroe County shares sales tax revenue under a formula established over 20 years ago through the Morin-Ryan agreement. That agreement, which involves all municipalities and school districts in Monroe County, is based on percentages. It's established in state law. The school districts believe the FAIR plan alters the formula because it changes the percentage of sales tax revenue they receive, says Jody Siegle, executive director of the Monroe County School Boards Association. And because it's a state law, she says, it's not within the county's right to do that.

Brooks presented her plan September 26, and that same night it was approved by the County Legislature's Republican majority. Under the plan, the county will give the state a portion of its sales tax revenues. In return, the state will assume the county's share of Medicaid costs. The plan would cause municipalities in the county to lose sales tax revenue, but Brooks has pledged to make up the lost revenue for towns, villages and the city. But school districts, Brooks has said, can make up the lost revenue with increases in state aid.

District leaders say that's not the case. They will have to raise taxes or cut staff or programs to make up the difference, they say. Estimated losses range from about $294,800 in Wheatland-Chili to over $4 million in Greece. And tax rates could increase in the range of 3 percent to 6 percent, they say.