Earlier in the legislative session, the House approved a bill that would change Missouri's income tax brackets to take account for inflation.
The bill would have changed the brackets for the first time since 1931, when they were first set up.
When the bill was passed on to the Senate, it was made part of the now-vetoed tax cut SB 509. Lawmakers will likely begin work on an override attempt on Monday, just as Gov. Jay Nixon is expected to return to Springfield to further the discussion about his decision.
"What's happening now is we accidentally bump people up into higher tax brackets, and they should not be bumped up into higher tax brackets," Rep. Paul Curtman (R) said.
Curtman introduced the original bill and said he hopes it becoming part of the tax cut will give weight to what he says is a need for tax reform.
"Considering the issue with our tax brackets and how archaic and out of date they are, I think that lends credibility to the argument that our tax policy in our state altogether needs serious, serious reform," Curtman said.
Missouri's top income tier is $9,000, which means most everyone is taxed at the 6 percent maximum rate.
The broad tax cut bill, SB 509, would cut the max rate by a half percent and allow for a 25 percent business deduction in 2017, if the state's revenue increases by $150 million over the past three years.