Linn County's three-member board of commissioners wrote today to Gov. Kate Brown, asking her to scrap her ambitious plan to increase Oregon's minimum wage.

The three commissioners, Roger Nyquist, John Lindsey and William Tucker, say the governor's proposal violates the Oregon Constitution's prohibition of unfunded legislative mandates and, perhaps more importantly, would cost Linn County $2.25 million a year that the county doesn't have.

Lawmakers' willingness to take on the task of pushing a minimum wage bill through the 35-day session that begins Feb. 1 stems in part from a desire to head off a ballot measure that would raise the minimum wage faster and with less flexibility.

Legislative leaders, including Senate President Peter Courtney (D-Salem) and House Speaker Tina Kotek (D-Portland), have responded enthusiastically and pledged to try to find the votes to pass Brown's proposal into law.

Brown proposed a tiered system that would push the minimum wage inside the three metro-area counties to $15.50 an hour by 2022, while boosting the wage in other counties to $13.50.

The Linn County commissioners, all of whom are Republicans, say they hope that won't happen.

Today's letter highlights one of the unknowns about Brown's proposal—the cost to state and local government. The Linn County commissioners say the cost to local government "is in the range of $450 to $500 million a year," although they don't cite a source for that estimate. (The largest city in Linn County is Albany—about an hour south of Portland.)

The Legislative Fiscal Office, which prepares estimates of the cost of new legislation, has not yet released its analysis of Brown's measure.

"Based both on the State Constitution and the lack of financial resources to pay for a minimum wage increase, we request that you forgo taking action on a minimum wage package in the upcoming 2016 session," the commissioners wrote.

Brown's spokeswoman, Kristen Grainger, says Brown will proceed as planned.

"Not only is a minimum wage increase constitutional," Grainger says, "it is good public policy."