The National Labor Relations Board has ruled that a Twin Cities Jimmy John’s franchisee violated the union organizing rights of six employees by firing them for publicly protesting the company’s lack of sick leave.

The decision late last week by the NLRB upholds an April 2012 ruling by a federal administrative law judge, and also calls for the six workers allied with the Industrial Workers of the World (IWW) to be reinstated and given back pay.

MikLin Enterprises, which owns 10 local Jimmy John’s, had appealed the administrative law judge’s decision to the NLRB’s full board in Washington. One member of the three-member board dissented, finding that MikLin didn’t violate labor law.

MikLin can appeal the NLRB’s decision in federal court.

“We’re reviewing the decision and our options at this time,” said Rob Mulligan, a MikLin co-owner, declining to comment further.

Erik Forman, one of the fired workers, said in a statement that “the NLRB has said what the public already knew: workers have the right to speak out about their working conditions, particularly when those working conditions mean that customers might get food served by a sick worker.”

The union’s protests emphasized that without paid sick leave, workers were forced to work while sick, potentially contaminating food.

Jimmy John’s workers tried to organize MikLin’s restaurants in 2010, falling just short of victory in an unusual union campaign. Unions rarely try to organize fast-food workers, largely because they are highly transient in their jobs. And the IWW is a militant, grass-roots union outside of the mainstream of the labor movement.

In October 2010, Jimmy John’s workers rejected the union by two votes, 87-85.

After the election, pro-union Jimmy John’s workers continued their organizing campaign, often emphasizing their lack of paid sick leave, a common policy in the restaurant industry.

In early 2011, pro-union workers placed posters around town displaying two identical Jimmy John’s sandwiches, with one described as made by a healthy worker, the other by a sick worker. “Can’t tell the difference?” the poster said. “That’s too bad because Jimmy John’s workers don’t get paid sick days.”

MikLin fired six workers and issued written warnings to three others involved in the poster campaign. The company has argued that the posters were “disloyal,” and therefore were not protected speech under federal labor law. One of the three NLRB board members agreed. But not the other two.

The posters were not so “disloyal, reckless or maliciously untrue” as to lose the protection of labor law, the NLRB ruling said.

“Indeed, any person viewing the posters … would reasonably understand that the motive for the communications was to garner support for the campaign to improve the employees’ terms and conditions of employment.”

The NLRB also ruled that MikLin violated labor law when three of its supervisors encouraged employees and other supervisors to harass or disparage David Boehnke, a Jimmy John’s worker and leader of the union-organizing effort. Boehnke was also fired because of the poster campaign.