Gov. Mark Dayton's budget director on Wednesday blasted legislative Republicans for relying on what he called "alternative math" in their spending proposals, which he said would hurt critical services provided by the state of Minnesota.

Commissioner Myron Frans of Minnesota Management and Budget said he would advise Dayton to veto the Republican-crafted bills, which together comprise the GOP's blueprint for spending more than $40 billion in taxpayer funds in the next two years.

With about six weeks left in the legislative session, Frans' comments — and an equally sharp response from House Speaker Kurt Daudt, R-Crown — raise the prospect of the kind of politically contentious, messy finale that in recent years produced multiple special sessions and a government shutdown.

"This is setting up a dynamic that just doesn't look very fruitful," said Frans, who alleged that the Republican budget measures contain "fake savings."

Daudt responded with his own charge of "fuzzy math" from the administration and noted their criticism came before Republicans even finished approving all the budget measures. House and Senate votes on a series of spending measures have come in recent days, accompanied by lengthy debates.

"The governor talking about vetoing bills before we've even passed them takes this rhetoric here at St. Paul to a whole new level," Daudt said.

Minnesota is projected to have a $1.65 billion surplus over the next two-year budget cycle, and Dayton and GOP leaders are split on how best to use that money. Dayton's $46 billion budget plan includes new spending on priority areas like education and transportation and modest tax breaks for some Minnesotans, and it leaves about $200 million on the state's bottom line.

House Republicans would spend about $1 billion less on state programs than Dayton and propose to use the bulk of the surplus — $1.35 billion — on tax cuts and credits. Senate Republicans approved a $900 million tax cut, spending increases on transportation and targeted cuts similar to those in the House plan. Both the House and Senate would reduce or cut spending on a wide range of state departments and programs.

Senate Majority Leader Paul Gazelka, R-Nisswa, said his plan takes "purposeful" steps to set aside money for new spending needs.

"The Senate budget is fiscally responsible and finishes a number of things left undone by the previous Legislature, like tax relief, long-term funding for roads and bridges, and starting to unwind the damage done to our health care system," he said.

Republicans have also noted that their plans boost spending on Dayton priority areas like health and human services by about $2 billion from the current budget cycle.

But Frans and Human Services Commissioner Emily Piper said those claims are misleading because the GOP budgets don't account for growth in current programs driven by inflation and other factors.

By that standard, they said, the Republican human services budget would leave the Department of Human Services facing a $600 million reduction, likely forcing cuts to state facilities and programs for people with mental and developmental disabilities.

The cuts would aggravate a shortage of psychiatric beds and potentially create a large backlog of people waiting for state-funded services that help them live more independently in the community, Piper said.

"This will have real consequences for people all across Minnesota who rely on these services being available," she said.

Of immediate concern, she said, are 12,000 people served by DHS-operated facilities and programs, including acute psychiatric hospitals and 120 smaller group homes. Many have highly complex psychiatric and developmental disorders, and their needs cannot be met by private sector providers. The Senate budget bill would cut funding to such programs by $40.9 million and would force the state to slash more than 200 jobs and limit services, DHS officials said.

Responding to questions about those cuts, Daudt faulted Dayton for expanding spending in human services and other areas — and for his "inability to make the departments operate more efficiently and effectively."

Daudt, considered a top GOP prospect for governor next year, suggested Minnesotans want someone other than Dayton making spending decisions for the state.

"Almost one in five Minnesotans now are on medical assistance," he said, "and if the governor thinks that's great and good prosperity and that's how Minnesota should operate, I think Minnesotans need to start looking for a new governor."

Staff writer Chris Serres contributed to this report.

Erin Golden • 612-673-4790