For the first time in 25 years, State Capitol watchers have been catching glimpses this session of an intra-DFL fight over a tax bill. But unlike the brawls of yore, this one isn’t about rates, deductibility or extensions. According to a participant — Gov. Mark Dayton, back at the Capitol on Tuesday for the first time since hip surgery on Valentine’s Day — this fight is over a building.

Dayton seemed a bit breathless as he set aside his crutches and faced reporters for the first time in five weeks. But he was in feisty rhetorical form as he accused Senate DFLers of delaying a tax relief bill in an attempt to spur House approval of a proposed new Senate office building. The DFL governor told legislators last week that the tax bill had to be on his desk by today to allow its changes to smoothly go into effect retroactively for tax year 2013.

Tying tax relief to the $63 million office building is “inexcusable” and “unacceptable,” Dayton scolded.

A new building is Senate DFL leaders’ proposed remedy for the loss of at least 14 Senate offices as the Capitol is renovated. That $250 million project is in progress and is at risk of delay if a decision about Senate quarters does not come soon.

The House Rules Committee to date has withheld required action on the proposed building. The Senate, by Dayton’s telling, has delayed action on a House-approved $500 million tax relief bill in retaliation. Dayton, who agrees that a new Senate building is warranted, told reporters he wants the issues decoupled and a tax bill on his desk ASAP.

It won’t come today. But it could arrive Thursday, Senate Majority Leader Tom Bakk told reporters about an hour after Dayton’s return to his bully pulpit. Bakk denied that the Senate was delaying the tax bill as a negotiating tactic. But if that bill was headed for the Senate floor on Thursday all along, its itinerary was a closely held secret before Dayton’s tongue-lashing. One wonders: If Dayton gets that much responsiveness while still on crutches, what might he accomplish at full strength?