Osmo Vänskä was in London last week, earning sterling reviews for conducting the BBC Symphony Orchestra at the Proms festival in Royal Albert Hall.

Vänskä, who returned to Minneapolis over the weekend, has been a favorite at the Proms for years, including the triumphant weekend in 2010 when his Minnesota Orchestra played Beethoven's Ninth and the music director told musicians, donors and board members: "It is such a privilege to be a conductor when you are standing in front of the Minnesota Orchestra."

Yet the orchestra that has given him such pride, joy and international renown has become a source of anguish for Vänskä. He said he will resign if a long, bitter labor dispute is not resolved in time for him to get musicians back on stage by Sept. 30 — to play concerts and to rehearse for high-profile dates in early November at Carnegie Hall.

Unless he changes his mind, Vänskä's fate with the Minnesota Orchestra could be determined in the next week.

By threatening to quit, Vänskä created the single greatest leverage point in a fight that has dragged on to become one of the most bitter and protracted orchestra shutdowns in U.S. history. The dispute has seen many key players depart for other orchestras. It forced cancellation of the entire 2012-13 season and threatens the start of another year.

Board leaders surprised observers last week by saying publicly that Vänskä might have to go, so strong is their belief that musicians must make salary concessions.

Blois Olson, a spokesman for the musicians, said Monday, "We want to maintain and build on what we have built, and Osmo is a part of that." The union continues to push for lifting the 11-month lockout for a negotiating period that would put the band back on stage for four months and preserve Carnegie. The board has rejected what it calls a short-term answer to a long-term problem.

Since he was hired in 2003, Vänskä has elevated the Minnesota Orchestra to a level of prestige it had not enjoyed for decades. Recordings of Beethoven and Sibelius have been nominated for Grammys; concerts in New York, London and European musical capitals have drawn rave reviews.

"When the Minnesota Orchestra engaged Vänskä, it was quickly understood in the field that they achieved a coup," said cultural and music historian Joseph Horowitz.

After hearing the ensemble play in Carnegie Hall in 2010, Horowitz was impressed. "He had created a singular instrument," Horowitz said. "The Minnesota Orchestra under Vänskä wasn't generic, but specific in style and sonority, and that's pretty rare nowadays."

Arrived in 2003

A native of Finland who built his reputation with the Lahti Symphony Orchestra, Vänskä, who is now 60, moved to Minneapolis and lives near the Mississippi River. In 2009, he signed a contract extension through 2015, which if he completed would make him among the longest-tenured music directors of the Minnesota Orchestra or its predecessor Minneapolis Symphony.

During the lockout, he has conducted widely across the United States, Europe and Asia. When he's in town, Vänskä has met regularly with management on season planning and other administrative matters.

Friends protect his privacy, declining to comment on his state of mind. "I'm just not comfortable sharing private conversations with a friend that I support and admire," Ronald Lund, a lifetime director, said in an e-mail.

Judy Dayton, a key orchestra benefactor, also asked not to be quoted for this story. In February, Dayton and Minneapolis Mayor R.T. Rybak hosted a concert to celebrate the orchestra's Grammy nomination for a Sibelius recording. It was Vänskä's first and only concert with the orchestra in more than a year.

"Osmo and I worked hard on setting the appropriate tone," Rybak said. "He put himself on the line for what he had hoped would be a way to break the dam, and we both were disappointed that the effort didn't have more impact."

Vänskä spoke briefly to reporters before that concert, the only time he has taken questions about the contract dispute. Asked if he would get involved in negotiations, he said, "No, I have enough headaches without that."

Yet statements that have become public put him squarely in the middle of the orchestra's mess. Last November, he implored musicians and the board to "find a way, talk together, listen to each other and come to a resolution of this dreadful situation." On April 30, he dropped the bombshell about Carnegie in a letter to the board.

"In the case Carnegie Hall chooses to cancel the Minnesota Orchestra's concerts this November ... then I will be forced to resign my position as Music Director," he wrote.

Unusual to go public

It is rare but not unprecedented for a music director to get publicly involved in a labor dispute. During the six-month strike at the Detroit Symphony in 2010-11, Leonard Slatkin kept his public remarks circumspect, although he was active behind the scenes trying to bring people together, said Mark Stryker, music critic for the Detroit Free Press.

One of the more dramatic incidents occurred in Houston, in 1977, when music director Lawrence Foster told musicians during a lockout that he was "100 percent behind them," said Jim Medvitz, a retired orchestra administrator who was a librarian at Houston. Foster was dismissed and has since worked almost exclusively out of the United States.

"This has happened before when music directors get antsy and insert themselves," Medvitz said. "Boards don't like to be pressured like that."

Greg Sandow, a critic and composer who writes on the future of classical music, is more forgiving considering the circumstances in Minnesota. "I can't imagine why he would want to stay," Sandow said. "It's not unreasonable for him to think, 'Let me put my weight on the scales.' "

Sandow said he believes Vänskä would not lack for work if he did leave Minnesota.

"Conductors are a commodity beyond price," Sandow said. "Orchestras schedule years in advance and most of the gigs will be taken, but stuff will certainly come up."

The repercussions of a Vänskä resignation probably would last for years.

"It's not easy to hire a musical director who has such a musical impact," Horowitz said, referring to Minnesota and Vänskä. "And it's not easy to do it twice."

Graydon Royce • 612-673-7299