Undeterred by a last-minute plan spearheaded by House Speaker Beth Harwell, Gov. Bill Haslam’s gas tax plan cleared yet another legislative hurdle Tuesday.

With a voice vote, Haslam’s proposal, which seeks to raise the state’s tax on gasoline and diesel fuel over a three-year period, was approved by the House Finance, Ways and Means Committee.

Beyond approving the governor’s bill, a competing plan advanced by Harwell, Rep. David Hawk, R-Greeneville, and others that would have used general fund revenues instead of a gas tax increase to pay for the state’s $10 billion backlog in road projects failed to gain enough support and was ultimately held back by Hawk.

The move sent a blow to House leadership — including Harwell, who is considering a race for governor — who had been working on an alternative plan for some time.

The alternative proposal, which came in the form of an amendment sponsored by Hawk, would have diverted a portion of the money generated through the sale of new and used vehicles, increased car registration fees and imposed taxes on hybrid and electric vehicles.

Haslam and Senate leadership have criticized any plans that mostly rely on using the state's general fund, citing concerns about any future economic downturns.

The governor’s plan seeks to raise the tax on gasoline by 6 cents and calls for various cuts to the state’s sales tax on groceries, as well as the franchise and excise tax. The Senate version of the bill also features property tax relief for eligible veterans and the elderly. The House recently removed the property tax relief portion from its version of the measure.

The House finance committee’s approval of Haslam’s bill ensures the measure could receive a vote on the House floor, barring any last-minute legislative high jinks.

The committee's final action came hours after the measure was initially taken up. After Hawk introduced his amendment earlier in the day, the committee took a brief recess to allow several of the panel's Democrats to discuss the matter inside House Republican Caucus Chairman Ryan Williams' conference room. After the Democrats had a private discussion with Hawk, the committee briefly reconvened before ultimately deciding to take yet another break to allow another legislative panel to hold its meeting.

During the intermission, House Minority Leader Craig Fitzhugh, D-Ripley, said the legislature has set a precedent by having a dedicated fund to pay for the state's roads and infrastructure needs. "I see no need now to change all that because it puts the rest of our general fund at risk," he said.

After the committee returned shortly before 5 p.m., Rep. Gerald McCormick, R-Chattanooga, moved to reject Hawk's proposal, which led the Greeneville Republican to withdraw his amendment.

McCormick said because Hawk's amendment would have completely rewritten the bill, the committee should be leery of taking such action.

"I'm really afraid that we could make some serious mistakes doing that," McCormick said.

Despite pulling back his amendment, Hawk vowed to continue to fight over the measure on the House floor.

"I will state that this issue is far from being done. We will have a conversation on the floor about how we need to better fund transportation and what is the most responsible way to do that as we serve our constituents," Hawk said. "That's a promise. We will have a debate on the floor, and we will bring an amendment to the floor."

Hawk's sentiment was shared by Williams, R-Cookeville, and House Majority Leader Glen Casada, R-Franklin, who called the alternative proposal the "best plan" after it failed to gain traction in committee.

"In the legislative process, the majority rules," Casada said. "We'll see what the majority wants to do on the House floor."

The House committee's move came one day after the chamber's Republicans took a straw poll using small sticks to anonymously vote on the IMPROVE Act. Thirty members were in favor of the proposal, 37 against and six Republican lawmakers did not vote in the poll, Williams said Tuesday afternoon.

If just 30 Republicans remain on board with the governor's proposal, Haslam would need 20 out of the chamber's 25 Democrats to ensure passage of his signature piece of legislation in the House.

Harwell said, "In light of the caucus vote, I think it would be wise to offer an alternative to the members, in order to keep this important conversation of infrastructure funding moving forward."

Williams said the goal for Republicans remains to find the best plan, even if it comes on the House floor.

"Unfortunately we're rounding third and headed home and it's very difficult to do that at this late time," he said. "Hopefully we can come up with a solution that more Republicans are in favor of."

With the House finance committee's vote on Tuesday, a total of 25 Republicans and nine Democrats have voted in favor of the IMPROVE Act as it has made its way through the legislative process. Just two Democrats and eight Republicans have voted against the governor's plan, according to voting records.

With the Senate finance committee expected to take up the governor's proposal on Thursday, the House and Senate could each take up the measure on their respective floors as early as next week.

Reach Joel Ebert at jebert@tennessean.com or 615-772-1681 and on Twitter @joelebert29.