BOSTON — The start of a program to equip 100 Boston police officers with body cameras has been delayed so a judge can consider a request from the city’s largest police union to temporarily halt the program.

An agreement with Boston’s largest police union to have 100 officers wear body cameras was praised as a step toward greater accountability. But by Thursday’s scheduled rollout, not a single officer had volunteered to wear one. Damian Dovarganes/Associated Press

The pilot program was expected to begin this week after months of negotiations between the Boston Police Patrolmen’s Association and the city. The sides reached an agreement in July calling for 100 officers to volunteer to wear cameras for six months.

But when no officers volunteered, Police Commissioner William Evans assigned officers to wear the cameras. That union then filed a lawsuit alleging the city violated the agreement.

A hearing on the union’s injunction request is scheduled for Sept. 6.

Police spokesman Lt. Detective Michael McCarthy said Wednesday that the city agreed to delay the start of the program until Sept. 12.

John Becker, a lawyer for the union, said the union is not attempting to stop the program, but objects to the decision to order 100 officers to wear cameras when the union’s agreement with the city called for volunteers.

“We’re supportive of the program,” Becker said.

“But you can’t have a process where you spend eight months negotiating an agreement, then when one thing doesn’t go as expected, everything gets thrown away,” he said.