Missouri's veto session begins September 11.
It would lower the state's top personal income tax rate to 5.5 percent from 6 percent.
The corporate tax rate would be lowered 3 points to 3.25 percent.
Nixon has traveled the state this past month asking for voter support for his veto.
Now, a group called Grow Missouri is making the rounds to explain why Republicans want to override the governor's veto.
"If we continue to just not do anything, we may have the best educated workforce in Missouri, and then we'll educate all our workers so they can find jobs in other states," State Representative for the 54th District Denny Hoskins (R) said. "That's not what we want to do."
Nixon's supporters say House Bill 253 would hurt education, mental health care and other social services by taking away millions of dollars.
The override would require the support of all 109 Republicans in the House.