Minnesota businesses and labor unions, at odds over increasing the state’s minimum wage, found rare common ground Friday against a proposal by Senate DFLers that would let voters decide by constitutional amendment if future hikes should be linked to inflation.

“We’re here to oppose legislating through the Constitution. We’ve already elected people to support us,” Ben Gerber, a lobbyist for the Minnesota Chamber of Commerce, told a Senate panel.

“The Constitution is not for giving specific guidelines to businesses in Minnesota,” said Jennifer Schaubach, legislative director for the Minnesota AFL-CIO.

Raising Minnesota’s current $6.15-an-hour minimum wage is a top priority for DFLers in charge at the Capitol, but the effort has been bogged down for months by differences between the House and Senate. While negotiators have agreed on a jump to $9.50 an hour, House DFLers want to guarantee subsequent hikes by indexing them to inflation.

The DFL’s labor allies badly want that provision, but it lacks sufficient support from DFL senators. An alternative plan, co-sponsored by Senate Majority Leader Tom Bakk, would take the decision on inflation out of the legislative arena and instead put it before voters via a constitutional amendment in 2014.

“We do not have the support in the Senate to put indexing in statute,” Bakk said Friday. “My hope was we could offer an alternative to provide an opportunity to index the minimum wage.”

While Minnesota’s minimum wage is $6.15 an hour, most employers are required to pay the federal minimum wage of $7.25.

The Senate DFL proposal united political forces typically at odds. At the Senate committee hearing, more than a dozen lobbyists and activists from business groups, labor unions, faith groups and various progressive causes aligned to call it a terrible idea.

“Voters entrust elected officials to make challenging decisions for the common good,” said Jamie Pfuhl, president of the Minnesota Grocers Association. She said automatic minimum wage hikes would be “severely detrimental” to the owners of the 1,100 grocery stores represented by the association.

On the other side of the issue, but in agreement against a constitutional amendment, was Jeff Bauer, director of public policy at the Family Partnership, a Minneapolis-based group that advocates for vulnerable children and families. Bauer said the low-wage workers who would benefit most from regular minimum wage hikes would not have the luxury of volunteering for a political campaign to pass it.

“That dad who only sees his kids for a few minutes between his second- and third-shift jobs doesn’t have the time to go knock on doors for a ballot initiative for seven months,” Bauer said.

The chief sponsor of the constitutional amendment, Sen. Ann Rest of New Hope, said putting it on the ballot would not prevent the House and Senate from separately hiking the state minimum wage from $6.15 to $9.50 — or even higher.

“Then if voters approved indexing, you’d have a new baseline to rise from,” Rest said. She and Bakk both said that if the inflation index is only in statute, and not the Constitution, that it would become a political football if Republicans regain legislative majorities.

DFL senators have been reluctant to back indexing out of concern it would be too great a burden on some Minnesota businesses, particularly those in rural areas or in cities that border neighboring states with a lower minimum wage.

“What this bill does today is open a new chapter,” said Sen. Matt Schmit, DFL-Red Wing. “This may be our only path forward, and we have to be open to that path.”

Republican senators called the amendment a political stunt. Gov. Mark Dayton and House Speaker Paul Thissen, both DFLers, said separately Friday that they disagree with pursuing a constitutional amendment on the issue.

“This shows a failure of leadership,” said Sen. Gary Dahms, R-Redwood Falls. He said by throwing the question to voters, the DFL would send a message that it doesn’t view a minimum-wage increase as urgently as do many of its allies.

The Senate Jobs, Agriculture and Rural Development Committee approved the amendment on a split vote Friday and sent it to the Rules Committee, which Bakk chairs. He cited a recent analysis by the magazine State Legislatures that found that in 10 of the 11 U.S. states where the minimum wage is indexed to inflation, it became law by voter approval.

With House and Senate negotiators stalled over their differences, Bakk said he and Thissen would likely have to get personally involved in talks next week. In addition to the dispute over indexing, negotiators also haven’t settled questions about what size of business the minimum wage would apply to, or a possible exemption for agricultural workers.

“I’d like to make a deal,” Bakk said.

Bakk himself has been a critic of what he’s called excessive constitutional amendments in recent years, and has sponsored a separate amendment that would make it harder for lawmakers to forward amendments to the ballot. But he said the indexing issue meets his own test for being important enough to put to voters.

Bakk said that if the question of indexing is on the November ballot, he would personally vote in favor.

“I do think it would provide some protection for those low-wage workers,” Bakk said.