ST. PAUL — Construction of a new office building for Minnesota senators is moving along, but the politics surrounding it remain messy as Democrats and Republicans girded again this week over the project’s $90 million price tag and how to pay for it.

Senate Democrats included money in a state budget bill this week to start leasing the $90 million facility for its expected opening next year. The tab is $13 million for 2016 and 2017 and about $8 million a year thereafter. Cleaning and running the building consumes about $2 million annually after it opens.

But the Republicans who control the House didn’t put any money for the building in their own state government budget bill, leading Senate Majority Leader Tom Bakk to issue a warning about the risks of not paying off the bonds sold to cover construction costs.

“If anybody around here thinks we’re not going to appropriate money to pay for those bonds, they’re going to put the state’s credit rating at risk,” the Cook Democrat said. “I don’t think there’s any question that’s going to get done.”

The Legislature approved the new project north of the Capitol in 2013. Democrats cited the need for a dedicated office and meeting space for the Senate — especially with the space squeeze created by ongoing renovations at the Capitol — but Republicans labeled it a poster child for wasteful spending.

It bears no resemblance yet to the “palatial” building GOP lawmakers and candidates pilloried on the 2014 campaign trail, but rather a skeleton of steel and concrete wrapped in tarp. Senior project manager Greg Huber said construction on the 290,000-square-foot building and parking ramp is nearly half-way done. Office framework for all 67 senators, Democrat and Republican, was just starting to be installed during a Tuesday tour.

In January 2016, the clanging and clatter of construction is scheduled to be replaced by the chatter of senators, lobbyists and citizens. But for now, Republicans are still expressing sticker shock.

Sen. Paul Gazelka, R-Nisswa, said GOP senators weren’t kept in the loop about the lease, including its cost. Gazelka argues the state should have paid for the building through a public construction borrowing package rather than leasing it from the builder.

“At the end of the day, there is no good remedy going forward,” Gazelka said. “We have no desire to leave a building half built.”