Field organizers from Sen. Bernie Sanders' unionized presidential campaign reached a payment agreement with campaign management late Monday.

The union representing staffers, the United Food and Commercial Workers Local 400, ratified by vote an agreement instituting a $42,000 annual salary and a 50-hour work week. The campaign also provides field staffers with 100-percent health care coverage. 

"We underwent negotiations. It has now, the offer, it has been accepted," Sanders told CNN in an interview Tuesday.

Last week, disgruntled staffers told The Washington Post that they were receiving inadequate compensation while the union and campaign were in negotiations.

Sanders has built a pro-union presidential platform, and has championed a $15 federal minimum wage.

Jonathan Williams, the communications director for the UFCW Local 400, told CBS News that the unflattering report misrepresented the negotiations.

"This was an amicable process. Both parties acted in good faith. Everything was running smoothly," Williams said. 

Sanders told the Des Moines Register that he was disappointed that details from the negotiations were leaked to the media. Williams agreed.

"It was unfortunate because we were in the middle of a process. A snapshot of it in the press really doesn't paint a complete picture," Williams said. "We don't know why someone would do something like that."

In May, Sanders' campaign was the first presidential campaign in history to unionize. Sanders has, so far this cycle, protested alongside workers from Walmart, McDonald's and Washington, D.C.'s Reagan National Airport fighting for a $15 federal minimum wage.