CHICAGO  — Gov. Pat Quinn plans to propose a ban on assault weapons in Illinois.

The Democrat will use his amendatory veto power Tuesday to include the ban in a bill related to ammunition sales. It would then be up to lawmakers to accept his changes or reject them.

The Associated Press obtained a copy of Quinn’s plans.

His proposal will face big hurdles in Illinois, even after the massacre at a Colorado movie theater renewed national debate about assault weapons.

Cook County’s ban has undergone legal challenges. The Illinois Supreme Court this year reversed lower-court rulings that found the ban constitutional, sending it to trial court.

Other gun-control measures have also failed in the General Assembly.