Bernie Sanders' campaign is battling its own unionized workers who are demanding the $15 minimum wage he wants to impose on the country

The campaign of Democratic presidential candidate Sen. Bernie Sanders (I-Vt.) is in a labor fight with its own union workers, who are demanding the $15 minimum hourly wage their boss is fighting to impose on every American employer.

What are the details?

Bernie 2020 made history earlier this year, when it became the first presidential campaign whose workers are represented by a union. According to The Washington Post, the employees did not waste any time in utilizing their collective bargaining rights.

The Post obtained emails and other documents showing the conflict over pay has been going on since May, the same month campaign workers ratified a contract to be represented by the United Food and Commercial Workers Union Local 400.

In a draft letter set to be sent to campaign manager Faiz Shakir as early as this week, the union argues that field organizers "cannot be expected to build the largest grassroots organizing program in American history while making poverty wages.

"Given our campaign's commitment to fighting for a living wage of at least $15.00 an hour, we believe it is only fair that the campaign would carry through this commitment to it own field team."

The letter explains that salaried field workers making salaries of $36,000 annually are working at least 60 hours per week, making their average pay less than $13 an hour. Union representatives go on to say, "many field staffers are barely managing to survive financially, which is severely impacting our team's productivity and morale. Some field organizers have already left the campaign as a result."

The union is asking for field organizer salaries be boosted to $46,800, and for 100 percent of health care costs to be provided for all campaign employees making $60,000 per year or less. Workers are also seeking mileage reimbursement for field staff at $0.58 per mile.

It is unclear whether Sen. Sanders is aware of his staff complaints.

The democratic socialist has been a longtime critic of big-money corporations and employers, decrying profit and urging wealth distribution. The Bernie 2020 campaign is reportedly sitting on a war chest of roughly $27.3 million in cash.

Anything else?

Sen. Sanders has been pushing for a $15 federal minimum wage for years, and the House passed its plan on Thursday.

According to a Congressional Budget Office report, the House Democrats' bill "would boost wages for about 17 million people — but it would also reduce business income, raise consumer prices and reduce the nation's output," Fox News reported.

The legislation is unlikely to go anywhere in the Republican-controlled Senate, but if were to become law, the CBO estimates real family income in the U.S. would be reduced by $9 billion in 2025.