26.030. Governor may veto appropriations — extent — exceptions. — The governor may veto any item or portion of any item of any appropriation bill or the whole thereof; except that the governor shall not reduce any appropriation for free public schools or for the payment of principal and interest on the public debt.
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(RSMo 1939 § 10905, A.L. 1945 p. 1428 § 58, A.L. 1959 H.B. 121)
See also Const. Art. IV § 26.