TRENTON - Senate President Steve Sweeney is introducing a constitutional amendment to raise New Jersey's minimum wage to $15 over eight years as well as a measure giving tax credits to employers who pay above the rate.

Sweeney unveiled the plan Tuesday in the statehouse alongside Democratic U.S. Rep. Donald Norcross, who represents Camden and will introduce a similar measure in Congress.

Democratic Assembly Speaker Vincent Prieto unveiled a proposal last week to increase the wage to $15 immediately, from $8.38.

Christie has said it would hurt the economy.

If voters approve Sweeney's proposal in 2017 it would raise the wage by a dollar per year until 2024. He says employers paying a dollar more than the wage would qualify for a 50-cent tax credit under legislation he plans to introduce.