Video (01:44) : The Republican state senator set to become the next lieutenant governor said Wednesday that she believes she can simultaneously continue to serve in the Minnesota Senate at the same time.

The Republican state senator set to become Minnesota’s next lieutenant governor said Wednesday that she intends to stay in the Senate at the same time, a matter of dispute with the Dayton administration that could create another constitutional mess at the State Capitol.

At a news conference, Sen. Michelle Fischbach of Paynesville said she’s consulted a Senate attorney about what will happen when Lt. Gov. Tina Smith resigns to fill U.S. Sen. Al Franken’s seat in Washington, D.C. Fischbach currently serves as Senate president, which puts her first in line to become the lieutenant to DFL Gov. Mark Dayton — a role she said she’s “honored” to take on.

“I was elected as the state senator from District 13 to represent those constituents and as prescribed by law, I will be planning on holding both of those roles and continuing to serve,” Fischbach said.

For Dayton, it’s an odd situation in a state that has long politically paired the governor and lieutenant governor. If the 70-year-old Dayton were unable to finish his term, which ends at the beginning of January 2019, then Fischbach would take over for him.

“I’ll do my best to stay healthy,” Dayton quipped Wednesday.

But Dayton and Senate DFLers believe Fischbach will have to resign her Senate seat. They contend that the state Constitution specifically prohibits one individual from simultaneously serving in both jobs. Dayton has asked Attorney General Lori Swanson to offer a legal opinion on the matter.

The constitution says the state Senate president ascends to the lieutenant governor's office. Senate President Michelle Fischbach, seen here Wednesday, said she expects to keep both jobs, a move that would help Republicans retain their edge in the chamber.

It’s important because of the potential to shift the balance of power in the closely divided Senate. Republicans currently hold a one-seat majority, with 34 seats. If Fischbach were to leave, it opens a path for DFLers to secure her seat in a special election.

Complicating it further: the planned resignation on Friday of DFL Sen. Dan Schoen following sexual harassment allegations. A special election for that seat will be held in February.

The Senate’s DFL leaders were quick Wednesday to outline their case for why Fischbach must leave the Senate, and to declare that two special elections were all but certain.

“This appointment, and the subsequent ascension of the Senate President to Lieutenant Governor, means the Minnesota Senate will likely face two special elections this winter,” Senate Minority Leader Tom Bakk, DFL-Cook, said in a statement. “The balance of power in the Minnesota Senate will be up for grabs.”

In the meantime, both parties are offering up their own legal interpretations.

In her news conference, Fisch­bach handed out a memo from a Senate attorney who argues that the subject was settled by an 1898 court case and backed up by historical precedent set by two senators who also served as lieutenant governor in the late 1920s and 1930s.

But Dayton and Senate DFLers highlight a provision in the Constitution that prohibits members of the Legislature from holding “any other office under the authority of the United States or the state of Minnesota, except that of postmaster or notary public.”

Additionally, they say a 1971 constitutional amendment approved by voters specifically changed earlier state law, which had listed the lieutenant governor as the “presiding officer of the Senate.” With that move, they say, the two positions became separate — and it became impossible for one person to serve in both roles.

Mary Jane Morrison, a professor at Mitchell-Hamline School of Law and author of a book on the Minnesota Constitution, agrees.

She said Fischbach made “an implausible argument based on an out-of-date case,” and said the attorney general, other senators or even a constituent could sue to have Fisch­bach removed.

Dayton said he plans to have lunch with Fischbach on Friday to discuss his plans.

Fischbach was hesitant to comment Wednesday on what she’d do as lieutenant governor if Dayton were unable to fulfill his duties, or on exactly how she’d split her time between the executive branch and her legislative role representing a St. Cloud-area district.

She said she expected the governor would not include her in critical decisions or expect her to carry out his agenda — particularly because they are “diametrically opposed” on some hot-button issues, like abortion.

Asked if she’d set aside her own opinions to carry out the policies of the governor, Fischbach said it was unlikely.

“I seriously doubt it,” she said.

Star Tribune staff writer J. Patrick Coolican contributed to this report.