Lyle Howe, Zinck's lawyer, entered the plea on his client's behalf today in provincial court in Dartmouth.
Zinck was arrested Oct. 2 after police stopped a vehicle on the street where he lives in the Halifax area.
He was charged with impaired driving and having a breathalyzer reading above the legal limit of 80 milligrams of alcohol in 100 millilitres of blood.
His trial has been set for Dec. 17.
Zinck, who represented the riding of Dartmouth North from June 2006 to June 2013, was previously convicted in the province's spending scandal.
He was sentenced to four months in jail and a year's probation on charges of fraud over $5,000 and breach of trust.