NASHVILLE, Tenn. -- A neighborhood battle over the proposed “Bredesen Bunker” is spilling over to Capitol Hill.

VIDEO: State Lawmaker Latest To Question 'Bredesen Bunker'

There's an expensive question being bantered around behind the scenes: Should millions of tax dollars pay for a banquet hall at the governor's mansion?

The underground addition that's come to be known as the "Bredesen Bunker" is now getting under some lawmakers’ skin, and the issue is following Tennessee first lady Andrea Conte around.

Conte is carrying the 13,000-square-foot load on her back. She was keynote speaker at a Young Leaders Council Luncheoen on Tuesday and used the time to address the mansion madness.

“The best way for this to work is go underground,” she told the crowd.

She said construction of Conservation Hall won't destroy the landscape and will be energy efficient by saving the state money. The issue is also concerning some legislators

“Restoring the mansion was a wonderful idea using private money. This has grown way beyond that,” said state Rep. Beth Harwell.

According to Conte, Conservation Hall's construction is covered by $4.8 million in private funds. She said $3.8 million in state funds is going toward making the facility handicapped accessible and improving the mansion's driveway.

But Harwell said she has heard up to $12 million will be coming from the state and can't get anyone to prove her wrong.

“I have called a number of offices; the budget department, the commissioner of finance and treasurer. They just haven't been able to supply those numbers,” Harwell said.

The General Assembly approved millions to go toward restoration and maintenance of government buildings, but Harwell said Conservation Hall wasn't specifically listed.

“The full amount that’s being spent on the mansion was never line-itemed within the budget,” she said.

Conte said she's gone through all the right channels. But when it comes to the Hall, there's room for questions.

“We just want to do what's best with the limited use of state dollars that we have,” she said.

Conte said the hall is needed because large dinners and meetings have been held in a tent in the past due to a lack of space in the mansion -- even in the winter. She said if you're trying to lure a CEO of a business to come there, that's not putting Tennessee's best foot forward.

Harwell said she is also concerned that the project did not go through the proper bidding process. Conte said she's had no legislators contact her with concerns and is open to talking with them.