CHICAGO (AP) — Illinois Gov. J.B. Pritzker is contributing an additional $51.5 million to a ballot initiative committee backing his constitutional amendment that would dump the state’s flat-rate income tax structure in favor of one that takes a bigger bite from the wealthy.

The contribution from the billionaire governor comes about six months after he contributed $5 million to the committee called Vote Yes for Fairness.

In November, voters will be asked whether the state constitution should be amended to allow a graduated tax structure instead of the current flat rate structure.