In 2014, Kenneth Brissette and Timothy Sullivan were beginning new chapters of their careers as fresh hires by the city’s new mayor, Marty Walsh.

Brissette, who had worked for the state film office, was the city’s new head of Tourism, Sports and Entertainment. Sullivan, a former leader of the Massachusetts AFL-CIO, was appointed the director of “intragovernmental affairs,” a title which apparently included acting as a liaison between the city and unions.

More or less immediately, according to federal prosecutors, both men entered in a conspiracy to extort Crash Line Productions -- the company behind the Boston Calling music festival, then gearing up for its second year on Boston City Hall Plaza -- into hiring union labor.

The men weren’t after money or other direct personal benefit -- instead, Assistant U.S. Attorney Laura Kaplan told a federal jury Tuesday, the men were seeking “payback [for] a union that was a political supporter and ally of their boss, Boston Mayor Martin J. Walsh.”

In her opening remarks in the trial of Brissette and Sullivan, charged with one count each of extortion of conspiracy to commit extortion, Kaplan told jurors that Brissette and Sullivan had used their power and influential positions in the Walsh administration to effectively threaten Boston Calling with the prospect of financial disaster if they were unable to get necessary permits because they had refused to hire members of Boston’s Local 11 stagehands union (IATSE).

“The defendants knowingly and willingly used Crash Line’s fear of economic harm to force Crash Line to hire nine [union] workers it didn’t want and didn’t need,” prosecutor Kaplan told jurors.

“That’s extortion. It’s a federal crime.”

Lawyers for Brissette and Sullivan painted a very different picture.

Attorney William Kettle, representing Brissette, told jurors that contrary to a story of two men conspiring to commit extortion, “this is case of two government employees doing their jobs.”

There were no threats, overt or implied by either Brissette or Sullivan regarding the festival’s permits or its decision to hire or not hire union labor, Kettlewell said.

“No threats, no payoff,” Kettlewell said. “The defendants had a lawful purpose …. To make sure the festival comes off without a union picket.”

And while his client did engage with the company regarding union relations, Kettlewell said, that was in the capacity of his job as city entertainment director – and because the stagehands union was threatening to picket the festival and erect a blow-up rat to protest the festival’s not hiring union labor – a prospect city officials very much wanted to avoid.

Kettlewell further suggested that the trouble Boston Calling was having obtaining final permits for its 2014 festival were tied to problems unrelated to whether it intended to hire unions – including concerns raised by the Boston police Department over incidents of intoxication and, Kettlewell said, a case of sexual assault at the festival.

Defense attorney Thomas Kiley, representing Sullivan, elaborated on those themes.

“There were zero threats. You’re going to hear zero use of force,” Kiley said.

“There is no evidence, zero evidence, that there was ever any articulation of a permitting problem” by Sullivan.

Instead, Kiley said, his client, Boston Calling and the stagehands union had a common goal which Sullivan, in his official and lawful capacity, was facilitating:

“There was a common goal, and the common goal was to have a successful Boston calling.”

Among the witnesses expected to testify in the trial, expected to last two weeks, are officials from Crash Line Production as well as from the television reality show Top Chef, which had been filming in Boston in 2014, around the same time that Boston Calling was seeking permits for its festival.

Neither Brissette nor Sullivan is charged with any crimes relating to Top Chef, but Brissette’s name came up frequently in the trial of four Teamsters charged with extorting Top Chef into hiring union labor in 2014 – those men were acquitted by a federal jury in 2017.

Among the witnesses who may be called is Boston Mayor Marty Walsh himself, although it is not clear that prosecutors will ultimately call Walsh to the stand.

Former Boston Police Chief Bill Evans also may testify, defense attorney Kiley indicated during opening remarks.