"Contractors are responsible for paying all applicable taxes," Browne said.
Ironically, the description of the law he cites is found on the Web site of Massachusetts Attorney General Martha Coakley - Brown's Democratic rival on Tuesday.
We asked specifically if the campaign provides health care coverage but have not received a response.
The most recent spending reports for Brown (R-MA) cover from Nov. 19 through Dec. 31 and list direct payments to staffers.
TPMDC spoke with several high-level campaign finance experts and both Republican and Democratic consultants familiar with compensation and campaign spending reports. They said the consulting designation seemed unusual but that there could be explanations, such as the person remaining a consultant so they could take on other political clients at the same time, or if they already worked for a consulting firm and were just contracting for the campaign.
But at least 10 of the 14 staffers who are listed in the consulting category do not seem to work for consulting firms, and aren't affiliated with any other campaigns. They also were paid far less than Eric Fehrnstrom, for example, the campaign's political strategist whose consulting firm also does work for Mitt Romney.
Experts - including a Republican known for work with campaign finance - said the contracting designation would allow the staffer to set their own hours and have autonomy from a boss that assigned a schedule. Another Republican source said the tough economy has led some consultants to take on more clients than they otherwise would, but that does not appear to be the case with the Brown campaign.
In one example, TPMDC asked the campaign for the title of one staffer listed under "strategy consulting" who was paid $538 on Dec. 21. The staffer is the volunteer coordinator, the campaign said.
Mary Anne Marsh, a Democratic consultant not affiliated with the race, said the filing appears to be a "cute little trick."
"Most advance people aren't consultants, and that is a convenient way of circumventing the responsibility to pay them health care," Marsh said.
The FEC does not regulate how campaigns designate their staffers.
Late Update: Coakley's campaign attempted to make political hay out of Brown's consultants over the weekend. "We already knew that Scott Brown didn't want to make health insurance more affordable for Massachusetts families and businesses," Coakley said in a statement. "Now we learn that he won't even make health insurance available for his own staff. If he won't stand up for the people he employs, how could we ever trust him to stand up for us?"
Brown campaign spokesperson Felix Browne dismissed the question in the Boston Globe this morning. "This is a silly issue," Browne told the paper. "The small group working on the Scott Brown campaign either has existing insurance or were compensated sufficiently to purchase it on their own."
At a campaign stop, Brown addressed the issue when asked about it by the Globe. "[H]e described the provisions for his workers' coverage," the paper reported, "emphasizing that they were happy with the arrangement."
(Update by Evan McMorris-Santoro)