A report from the Kansas Legislature’s nonpartisan research staff is sparking new questions about explanations for recent revenue shortfalls from Republican Governor Sam Brownback’s administration.

The legislative report released Tuesday said the estimates for income tax cuts championed by Brownback in 2012 and 2013 appear to have been understated in the state’s official revenue projections.

State tax collections in April and May of this year were $310 million short of the projections. The Department of Revenue has blamed disputes in Washington over federal tax policy that caused investors not to claim capital gains in 2013.

Secretary Nick Jordan stood by that explanation Tuesday.

The Legislative Research Department’s monthly report on revenues acknowledged the capital gains issue as a factor in the recent shortfalls but also cited understated estimates for tax cuts.