Gov. Bruce Rauner says a $1 billion tax cut should be the top priority for this year’s legislative session. The Republican said Wednesday it could be achieved by changing the way pensions are doled out to state employees.

But the pension changes are contentious and experts question whether a court would find it constitutional.

Rauner’s fourth budget address included his promised plan for a phased-in cut in last year’s income-tax increase. Lawmakers increased the rate from 3.75 percent to 4.95 percent to help pay down the state’s massive deficit. Rauner vetoed it but it was enacted anyway.

Rauner says enacting pension changes would mean “a nearly $1 billion tax cut” that would allow him to “start rolling back” the rate hike.