House Majority Leader Steny Hoyer (D.) on Thursday compared the situation of federal government employees still working during the partial shutdown to slavery in the 1800s.

"Yes we lament the pain that is being inflicted on the 800,000 people who work for the federal government. And the 440,000 people that are being asked to work with no pay," Hoyer said during a rally in Washington, D.C. "You know, back in the 1860s, they talked about working with no pay."

The comment, made to a group of federal union workers outside the AFL-CIO’s headquarters, was an apparent reference to when African Americans worked as slaves. It was met with a few shouts of approval from the crowd.

President Donald Trump and Congress remain at an impasse over funding for Trump's proposed wall along the southern border. The standoff has resulted in a partial government shutdown that is now in its 21st day. Over 800,000 furloughed federal government workers will go without a paycheck on Friday.

Trump gave an Oval Office address Tuesday night arguing that there is a crisis at the border and that a physical barrier is necessary in order to secure it. Speaker of the House Nancy Pelosi (D., Calif.) and Senate Minority Leader Chuck Schumer (D., N.Y.) have remained firm in their opposition to the wall. Although, cracks are beginning to form in Democrats' opposition to a wall or physical barrier of some kind.

During the government shutdown in 2013, government workers received backpay after it was resolved. The Senate passed similar legislation on Thursday, so federal workers will receive the paychecks they missed because of the shutdown.

"Shutting down the government is not a policy that should be followed. What if I ran for president of the United States and said, ‘vote for me, I will shut down your government?'" Hoyer said.