In a letter to the White House, 18 Democratic senators, including Elizabeth Warren (D-MA) and led by Bernie Sanders (I-VT), called on President Obama to join the nationwide movement to increase wages in some of the lowest-paying jobs.

Specifically, the group of senators urged the Obama administration to give preference to contractors who pay their employees “a living wage, offer fair healthcare and retirement benefits, grant paid leave for sickness and care-giving, provide full-time hours and stable schedules, and give workers a voice through collective bargaining so they do not need to strike to be heard.”

One of their main arguments focuses on the taxpayers and how the government giving contracts to low-paying companies ends up costing them more in the long run.

“The federal government continues to be America’s largest low-wage job creator, subsidizing poverty-level wages through taxpayer-funded contracts, loans and grants with private companies. To add insult to injury, many of these contract workers are forced to rely on public assistance programs to supplement their meager incomes. That means taxpayers are double-billed — once for the cost of the contract and then again for the cost of public programs like food stamps and Medicaid.

We believe that our taxpayer dollars should reward good companies that create middle class jobs for America, not companies that force workers to depend on public aid programs.”

The letter mentions how the Obama administration has praised companies like Costco as being “model employers” for paying their workers living wages and respecting “their right to organize unions.”

“Now it is time to declare that the federal government will invest our taxpayer dollars to incentivize model employers that commit to creating good jobs and to rebuilding America’s ailing middle class,” the senators wrote.

“With the economy rebounding and unemployment declining, now is the time to make sure hard-working Americans share in the rewards of our renewed prosperity,” the letter concluded. “We look forward to working with you to rebuild the middle class by having the federal government serve as a model employer.”

Click here to read the full letter.