Seward Community Food Co-op workers voted by an overwhelming count to unionize, becoming the last food retail co-op in Minneapolis to do so.

The vote Thursday was 191 to 12 to affiliate with United Food and Commercial Workers (UFCW) Local 653.

"I can't say in my 35 years working for Local 653 that I have ever seen a larger margin of victory in any union," said Matt Utecht, president of the local.

The Seward Co-op employs about 340 people at grocery stores on E. Franklin Avenue and E. 38th Street, and a cafe and food production facility on Franklin.

The Twin Cities has one of the largest concentration of food co-ops in the country, and Seward is the oldest and largest, with about 17,000 members.

Employees earlier this month marched for better wages and benefits and alleged that managers were retaliating against them for demanding union recognition.

On Friday, Seward Co-op said in a letter to members, "We want co-op owners to know that management is committed to [making] sure this process goes smoothly. The co-op management and the union have agreed that we have zero tolerance for retaliation directed at employees, whether they were in favor or against the union."

The UFCW pushed to organize workers at local co-ops after losing members in the 2014 exit of Rainbow Foods from the Twin Cities market. Linden Hills Co-op and the Eastside Food Co-op, each with about 85 employees, were unionized this year, and the Wedge Community Co-op, with about 160 employees, was unionized in 2015.

Seward Co-op general manager Sean Doyle said it has operated on a "living wage" model since 2007, meaning workers are paid more than minimum wage. The current living wage for a single adult in Hennepin County is about $11.40 an hour, according to a calculator by the Massachusetts Institute of Technology.

"We are looking forward to working with them [the union] and trying to find common ground and create a good workplace for our employees," Doyle said. "Unions are similar to co-ops in our mission to be for the people. We see them as partners, and we hope we can work together to ensure the co-op is here for another 40 years."

Doyle said he wasn't sure yet how his workers being unionized will impact the business, but he said the ­co-op's revenue has fallen in the past few years due to a more competitive market.

Since Rainbow's exit, Hy-Vee, Aldi, Trader Joe's and Fresh Thyme Farmers Market have all expanded in the Twin Cities. Seward's revenue in 2014 was about $34 million, but Doyle said he expects this year it will be about to $28 million.

"There are more options for people to buy groceries now than there were a decade ago," he said. "We still have a strong niche. Forty percent of our food is locally made and we think that will make a difference in the marketplace."

Staff writer Randy Furst contributed to this report.