Three and a half years ago, Walter Mondale, then honorary consul general of the local Norwegian consulate, co-authored a letter to the Norwegian ambassador declaring that the pay differential between a woman and a man at the consulate was “too large … unjust and embarrassing.”

Now the former vice president is embroiled in an acrimonious federal lawsuit over the woman’s allegations that she was paid $30,000 less than a man who was doing comparable work for the consulate.

Mondale is expected to be a key witness in a trial set for next month in St. Paul before U.S. District Judge Susan Richard Nelson.

The letter from Mondale is part of a fat court file describing the dispute between Ellen Ewald and the Norwegian Embassy.

Mondale, a former U.S. senator, vice president and ambassador to Japan, served as Norway’s honorary consul general in Minnesota from 2008 to 2010.

“My family’s from Norway,” he explained in an April 2013 deposition in the lawsuit. He said he had traveled to Norway and worked with the Norwegian leadership and its embassy, “so I think my connections there are pretty strong.”

Norway has had a diplomatic presence in Minnesota since 1906 and is home to nearly 900,000 people of Norwegian descent.

The roots of the dispute go back to 2007, when Norway announced it was closing its “career consulate” in Minneapolis for budgetary reasons. After a public outcry, it decided instead to create a “New Model Consulate” that was to include two new experts, one focused on innovation and business development, the other on higher education and research.

Six Norwegian institutions, including the country’s ministry of education and research and a national research council, put up about $250,000 to fund the two positions.

Mondale became the highest-ranking person in the consulate. Gary Gandrud, a partner in the Faegre & Benson law firm, was to be honorary consul/operational director.

Ewald took the educational post, inspired by the opportunities and because Mondale headed the consulate, she says. “I admired him throughout his life, precisely because of what he has done for women,” she said in an interview.

Ewald, 55, who spoke Norwegian, had a master’s degree in political science from MIT, and had lived and worked in Norway for 20 years. “We thought she was an excellent choice and would fit right in with what we wanted done,” Mondale said in his deposition.

The business post went to Anders Davidson, planning and business development manager for 3M’s International Operation, with an MBA from the University of Minnesota.

In the lawsuit, Ewald said she thought the money for the two positions would be split evenly between the two. She complained when she found out that Davidson was making $100,000 to her $70,000. Her three-year contract was not renewed in 2011.

Ending wage male-female pay disparities has long been a core issue for Mondale, who featured it in his unsuccessful campaign for president in 1984. At the funeral for Mondale’s wife, Joan, last month, Vice President Joe Biden, said, “she was great supporter of equal pay for equal work, just like you Fritz,” pointing to Mondale.

For an honorary consulate general to get involved in a dispute like this is unusual, says Prof. Larry Jacobs at the University of Minnesota Humphrey School of Public Affairs. Usually “they fly the flag,” he said, and show up at cocktail parties. Mondale’s involvement was “quintessential Mondale,” he said. “It sounds like what he did it is to take this honorary position more seriously than most [and] tried to give good service.”

The Norwegian Embassy says that Ewald was paid fairly and that she agreed to the salary.

“Commitment to gender equity is one of the defining characteristics of a remarkable career of public service for Mr. Mondale and he was one of the four people who recommended these salaries,” says Dan Wilczek, attorney for the Norwegian Embassy. Wilczek points out that six of Ewald’s eight claims have been dismissed by the judge.

On remaining claims, he said “Her gender had nothing to do with the wage she was paid. It was based on the market for the individual possessing the type of skills that were involved.”

Sheila Engelmeier, Ewald’s attorney, counters that the market study Norway touts was not a study and was inaccurate. She said she regards Mondale’s letter as the “single most important document in the case.”

Mondale testified in the deposition that he thought Ewald and Davidson were doing a “great job,” but learned she was very upset after discovering she was making much less than Davidson. “I never said we would pay equal amounts,” Mondale said. “In both cases, we tried to — we wanted it to work. And we tried to get figures that we thought reflected the economic realities in the market for the job that was involved.”

Still, Mondale defended his language in the letter calling the differential unjust and embarrassing. “We were putting pressure on our superiors to try to correct something that was a real problem for us,” he stated. “And to do that, we used charged language … We weren’t getting anywhere, we put some dynamite in the letter.”

Mondale is recovering from triple heart bypass surgery and was unavailable for comment.