ST. PAUL — Gov. Mark Dayton is threatening to veto a state agency budget bill if Republicans don’t agree to remove a part that would ditch candidate spending limits and undo current restrictions on where their donations originate.

The Democratic governor’s ultimatum came Monday and dealt with a proposed change in a House-passed budget bill. It would eliminate an income-tax checkoff program that gives candidates public subsidies for agreeing to spending limits. It also would remove caps on the number of checks candidates can take from political action committees and lobbyists.

House Minority Leader Paul Thissen, who appeared with Dayton, says the combined measures would drown out voices of average voters by making candidates more dependent on money from the most-connected givers.

Republican Rep. Sarah Anderson, the bill’s sponsor, says she’s standing by the proposal and called Dayton’s opposition to the bill “unfortunate.”