A coalition of labor unions and immigrant workers organizations is pushing a bill in Massachusetts to overhaul the state’s staffing industry.

If it’s adopted — almost half the state Legislature is listed as sponsors — the bill would impose a number of administrative obligations on staffing firms, and potentially limit some fees while raising costs. It exempts most professional workers, but it would apply to a broad range of workers, including nurses, clerical, blue collar, and similar. Violators could be fined.

Proponents, who were contacted but didn’t respond, are positioning the legislation as a “temp workers right to know bill,” highlighting provisions requiring staffing firms to inform employees for whom they’ll be working, how much they’ll be paid, where they’ll work, and what they’ll be doing.

“No such law currently existing in other states”

While on its face benign, other provisions of the bill limit some fees and essentially end temp-to-hire conversion fees. It puts a damper on the practice of shopping good candidates, by prohibiting candidate referrals without job reqs. Out-of-state staffing firms could be closed out of placing workers in Massachusetts unless they had an in-state office.

“There is no such law currently existing in other states,” says Stephen Dwyer, general counsel for the American Staffing Association. “It is more sweeping and more harmful than any, bar none.”