The Democratic governor says he plans to take action Wednesday on the legislation that he has previously indicated he likely will veto.
The measure passed by the Republican-led Legislature would gradually cut individual and corporate income tax rates.
It also would create a 50 percent deduction for business income that gets reported on individual tax returns.
Nixon said a month ago that the tax cut could drain hundreds of millions of dollars from state services.
Last week, Nixon raised additional concerns over an apparently inadvertent section that would repeal a sales tax exemption for prescription medicines. The governor says the repeal would cost consumers an estimated $200 million annually.