The City Council voted last week to approve a plan to redraw the lines in four city wards, and councilors are scheduled to take a second, final vote next week.
Supporters say a photo ID mandate would boost public confidence in Maine elections, but opponents, including Gov. Mills, say it would do far more harm than good.
The City Council was supposed to hold a public hearing on a plan to free up more parking for the Waterville Public Library by turning a portion of Appleton Street from two-way traffic to one-way.