ST. PAUL, Minn. — In a sudden reversal Thursday, Gov. Mark Dayton said he was open to expanding the scope of a storm-relief special session to include the repeal of a new sales tax on farm equipment repair.

Dayton announced his revised position during remarks at Farmfest in southern Minnesota, according to media reports. The special session has been penciled in for Sept. 9 and is expected to be done in a day.

On the Linder Farm Network radio program, Dayton called the farm tax "the biggest mistake" of the legislative session, saying it deserved to be addressed in an emergency session. The month-old tax on repairs to tractors and other agricultural equipment was expected to raise $28.6 million over the next two years.

"I hope the two Republicans will agree to include that and nothing else and if so we will get rid of it and clean up the mistake," Dayton said.

The disaster package would provide a state match for federal aid. Severe storms in June caused $17.8 million in damage and caused the largest power outage in state history. The relief would pay to repair public infrastructure in 18 counties.

Dayton's willingness to look beyond a disaster relief measure is a stark turn from two days earlier when he said other measures could wait until next year. On Tuesday, Dayton criticized efforts to put other topics in play as "grandstanding" and said everything else could wait until the next session begins in February.

"If we open that door in special session we'll be wide open for every other subject — many of which are entirely legitimate," Dayton said. "But we'll have another full-fledged session if we go that route."

House Speaker Paul Thissen and Senate Majority Leader Tom Bakk, both Democrats, sent a letter to colleagues saying they are on board with the two-item agenda, but said that's where they would draw the line.

"Members of both parties have raised other issues in the context of a possible special session," they wrote. "In the interest of delivering timely relief to the communities affected by the recent storms, along with farmers across the state struggling as a result of these and other weather events, we will limit the session to just these two items."

While Democrats have full statehouse control, they need GOP consent to suspend rules to contain the session to just one day. Without it, a session would stretch on for at least a few days.

Many in the GOP also want to scrap a new tax on warehousing services. That tax won't kick in until April, but some who work in the storage industry say it is already discouraging investment. Dayton said he would be on board with the warehousing tax repeal later on if lawmakers find replacement funding for the budget.

House Minority Leader Kurt Daudt, R-Crown, reveled in the Democratic retreat on one tax.

"Republicans agree that Democrats' tax increases hurt Minnesota families and farmers and they should be repealed," Daudt said. "By using special session to fix their mistakes, consider this a 'Do-Over' session for Democrats."