A plan to put an $18 million expansion of the Lawrence Public Library on the November ballot moved forward Tuesday night, but not before commissioners were urged to consider an alternative.

Lawrence resident Bill Mitchell asked commissioners to consider using a portion of the city’s share of the countywide 1 cent sales tax to pay for at least part of the project.

The idea came up briefly at last week’s City Commission meeting, but commissioners did not give it much consideration. When pressed by Mitchell on Tuesday, commissioners said they did not think the sales tax was a good choice for the library because the sales tax will continue to be needed for future parks and recreation projects.

Instead, voters will decide whether to increase the city’s property tax mill levy by 1.5 mills for 20 years to fund the construction of the expansion. Library leaders also are asking for another 0.5 mill to fund operations of a larger library.