WOONSOCKET — The city has issued a general order to its firefighters that says starting May 11, if they want to work a second job, they will need the permission of the chief or the public safety director.

Firefighters union officials blasted the order, calling it a violation of their contract with the city and possibly their constitutional rights.

Christopher Lambert, one of the lawyers who handles labor relations for the city, said the order was needed to make sure that in the wake of Fire Department layoffs earlier this year, the firefighters on duty would be ready and able to do their jobs.

“It’s been a concern for some time,” Lambert said.

The idea was first floated publicly in March, but Lambert said the city had waited on implementation because the order needed “to go through channels.”

Steven Reilly, president of Local 732 of the International Association of Firefighters, scoffed at Lambert’s claim that the order was prompted by a concern for public safety. He called it revenge.

“This is retaliation because we don’t have a contract,” Reilly said.

The nature of the firefighters’ schedule makes it possible for many to hold second jobs. They alternate two days of 14-hour night shifts with two days of 10-hour day shifts and then four days off.

The city and the fire union have been in a standoff for months over what the city says are needed contract concessions. Eleven firefighters were laid off in March to help close a city deficit. But Reilly said by June 30 the city will wind up paying about $88,000 more in overtime than it would have paid had the laid-off firefighters stayed on the payroll.

Joseph A. Andriole, a staff representative for the Rhode Island IAFF unions, said the order was a violation of the contact and the union would be filing a grievance next week. He said the city had no right to regulate the firefighters when they are on their own time, providing they show up for work on time, “ready, willing and able to perform their job functions.”

“I think this is political retaliation on the mayor’s part,” he said.

The order will take effect at 12:01 a.m. on May 11. It says that because of the city’s financial crisis and the need to maintain public safety, firefighters who want to work off-duty jobs will need the approval of Chief Gary Lataille or Mayor Susan D. Menard, who also serves as the city’s public-safety director.

The order bans work that that would involve using department time or resources, including the uniform, for personal gain; doing work that would normally be expected to be done for the city while the firefighter was on duty; any acts that would have to be reviewed or approved by the Fire Department or other city employee; and lastly, work that “involves such time demands as would render performance of his or her duties as a firefighter less efficient and effective.”

Reilly said the union’s position was that the city had no right to infringe on its members’ lives when they are off duty.

“I believe outside of work the only one who tells me what I can do and what I can’t do is my wife,” Reilly said.

jhill@projo.com