The new state office building that’s been the subject of political attacks for several years, and fodder for campaign hit pieces in 2014, is finally open for business.

The Minnesota Senate office building on University Avenue, directly north of the State Capitol in St. Paul, hosted several legislative hearings at the end of last week. DFL senators and their staff were mostly moved in as of Monday, as well as nonpartisan Senate offices including the Sergeant at Arms.

With Senate Majority Leader Tom Bakk as its chief legislative proponent, legislators and Gov. Mark Dayton approved $90 million for the building project at the end of the 2013 session, a decision that still reverberates politically.

“It’s always harder to do construction projects in the public eye,” Bakk said Monday, sitting in his new third-floor corner office that looks toward the rear of the Capitol. But he said the new facility would be much more effective at accommodating the public. It features larger hearing rooms, and greatly improved accessibility for people with disabilities.

Republicans relentlessly criticized DFLers for approving $90 million in state funds for the project. So far, Republican senators have refused to move into space that was ­earmarked for them in the new building.

With the Capitol in the midst of a massive renovation project, the new building features a temporary chamber that will house the Senate for the upcoming legislative ­session.

Bakk said the new building was necessary or “the Capitol would have been a Senate office building for another hundred years.”

Previously, much of the Capitol itself was given over to office space for senators and their employees; the new building has allowed for a vast expansion of public space in the Capitol, and will mean additional space for the governor and the House.