JEFFERSON CITY — Missouri lawmakers and transportation officials have long complained about inadequate funding for repairing roads and bridges across the state, but the House on Wednesday struck down a proposal that supporters said could've helped mitigate the problem.

The House voted 51-103 to scrap an amendment raising the state's gas tax by nearly six cents per gallon, pending voter approval in 2018. The proposal was largely along party lines with only 11 Republicans supporting the amendment.

The tax hike would have been added to a bill that won initial approval Wednesday allowing the state to tax propane fueled vehicles.

Lawmakers have floated proposals to generate more revenue for roads and bridges, including toll roads and sales taxes, but so far none have stuck. Amendment sponsor Rep. Greg Razer, a Democrat, said his proposal would help put more money into much-needed infrastructure improvements.

"It has time to have this discussion," Razer said. "This is the option to fix our roads and bridges. Let's not wait for a bridge to collapse."

Critics of the amendment said voters have repeatedly struck down tax increases, so the amendment likely wouldn't change much.

In November, voters rejected two controversial proposals to raise the state's lowest-in-the-nation tobacco tax, and in 2014 they rejected a sales tax increase for transportation.

Republican Rep. Paul Curtman on Wednesday called on lawmakers to reject the amendment, saying the state should look to use its dollars more efficiently instead of raising taxes.

The amendment would've raised the fuel tax from 17 cents to 22.9 cents per gallon. That's above the national average of 21.09 cents per gallon, according to the American Petroleum Institute.

Last year, the Senate passed a similar proposal, but that bill stalled in the House.

Missouri has the seventh-largest highway system in the country, but ranks 47th in revenue per mile. It also has one of the lowest fuel taxes in the nation and more miles of state highways than Iowa, Nebraska and Kansas combined, according to the Missouri Department of Transportation.

The state has more than 10,000 bridges. About 860 of them are in poor condition and more than 1,300 are weight restricted, according to the transportation department.