Joseph Dougherty, 73, former business manager of Ironworkers Local 401, was convicted by a federal jury Tuesday for ordering criminal acts of violence against non-union workers and jobs that employed non-union labor.

Dougherty was convicted on charges including racketeering, malicious damage to property by means of fire and use of fire to commit a felony, the Philadelphia U.S. Attorney’s Office said.

During his trial, prosecutors played phone conversations with Dougherty recorded by an FBI wiretap in which he directed other Ironworkers to attack or threaten contractors who employed non-union laborers.

“Did those guys hire our guy today?” Dougherty asked an underling about one project with non-union workers. “We’re not losing in Center City.”

Later, told the contractor has offered to hire two union workers, Dougherty responds, “Tell him to go f--himself.”

That contractor was eventually intimidated into staffing the entire project with workers from Local 401.

Dougherty is scheduled to be sentenced on April 29.

Dougherty, 73, was indicted in February 2014. Eleven other ironworkers were also indicted and subsequently pleaded guilty to using threats, violence and sabotage to secure jobs for workers from the local. Only Dougherty pleaded not guilty and went to trial.

Prosecutors said Dougherty lead a campaign of extortion and violence around Philadelphia for years, including directing other ironworkers to attack non-union laborers at a King of Prussia site with baseball bats, sabotage a Quaker construction site in Chestnut Hill and orchestrate the takeover of a small residential development in University City.

Charges related to the sabotage of the Quaker construction site were dismissed after the judge ruled there was insufficient evidence linking that incident to Dougherty, the Inquirer reported.

Dougherty is scheduled to be sentenced on April 29.