BEVERLY — Union workers have been standing with signs in front of the Cummings Center and handing out literature at doctors' offices this week to protest what they say is the use of nonunion workers to build a medical office building in Danvers.

The Massachusetts Building Trades Council says they are targeting the North Shore Physicians Group because some of their doctors will occupy the new building. The doctors' group has about 200 members with offices in 17 North Shore locations, including the Cummings Center.

The Trades Council sent out a press release saying, "These doctors have no problem sending ever-increasing medical bills to union health insurance plans and turning away patients without health insurance. But when it comes to the contractors building their own offices, it's how low can you go and we don't care if you have health insurance."

North Shore Medical Center in Salem, which owns the North Shore Physicians Group, denied that the group is using nonunion workers. In fact, the medical center said in a press release that neither it nor the North Shore Physicians Group are developing the property.

The medical office building is being built next to the Massachusetts General North Shore Center for Outpatient Care, which is affiliated with North Shore Medical Center and its doctors' group. But the office building is being constructed separately by a private developer and another doctors' group, the press release said.

"Neither the Medical Center nor its physician group has a role in the selection of contractors for the Medical Office Building project," the press release said.¬ 

North Shore Medical Center said it has an "excellent track record" using union labor, including on the Massachusetts General building in Danvers and the $30 million renovation project underway at Salem Hospital.

Union workers have been holding signs that say "www.northshorephysiciansexposed.com." The Web site provides a link to what it says are malpractice claims against North Shore Physicians Group doctors.

North Shore Medical Center says most of the doctors named are not members of the group. It says the union's "misdirected communications impugn the reputations of many fine North Shore physicians."