NASHVILLE, Tenn. (AP) — A proposal that would require Tennessee voters to show photo identification before they can cast ballots passed the House on Thursday despite a legal opinion from the state's attorney general that the Republican-led effort would violate the Tennessee and U.S. constitutions.

The measure sponsored by House Republican Caucus Chairwoman Debra Maggart of Hendersonville was approved 57-35. The Senate passed its version of the bill 21-11 in February, with only one Democrat voting for the measure.

However, state Attorney General Bob Cooper on Wednesday said in the opinion that without a provision to supply voters with free ID cards, the measure "unduly burdens the right to vote," and would constitute an unconstitutional poll tax.

Lawmakers must now work out minor differences in the legislation before it goes to Gov. Bill Haslam for his consideration. The Republican governor told reporters before the vote that he's unsure if he would sign the measure without a constitutional remedy.

"Obviously, the attorney general's opinion is very significant in that matter," said Haslam, adding that he first saw the opinion on Wednesday. "I do think that having a way to verify ... that the people are the people who should be voting is important to all of us."

Democrats have voiced concern that the measure will intimidate or otherwise disenfranchise legitimate voters, while Republicans have argued that it would ensure ballot integrity.

"We don't want to institute a poll tax, or any type of impediment," said House Minority Leader Craig Fitzhugh, a Ripley Democrat who requested the attorney general opinion.

Maggart said identification is a necessity in many cases, even for obtaining a library card, and voting shouldn't be any different.

"While this bill won't stop all voter fraud, it is a good bill to have in our tool box," she said. "We want to make sure that people have the utmost ... confidence in our voting process."

A separate Democratic measure to provide free IDs to people who can't afford them is advancing in the Senate, but its estimated price tag is nearly $200,000 in lost state revenues per year. Cooper's opinion notes that the Democratic measure "would appear to cure any challenge to the constitutionality" of the voter ID bill.

An amendment similar to the Senate Democratic proposal was among several measures proposed by House Democrats that failed Thursday. One would allow individuals 65 years and older to be exempt from purchasing identification.

Maggart said she has other legislation that she plans to use to address the cost of the photo IDs. She ignored the requests of some lawmakers to put the voter ID bill behind those.

"I think there needs to be some more work done on the legislation," said Republican Rep. Steve McDaniel of Parkers Crossroads, who didn't vote on the bill.

Present law allows voters to provide documents without photos such as valid voter registration certificates or social security cards.

Under Maggart's proposal, a person who can't show proper identification would be able to vote by provisional ballot, and individuals in nursing homes or group homes would be exempt.

The measure would also require a person who can't afford to purchase identification or has a religious objection to being photographed to "execute an affidavit of identity on a form provided by the county election commission in order to vote."