Washington DC - The Transportation Security Administration (TSA) is in the midst of a major crisis as hundreds of employees resign en masse amid a month-long shutdown of the Department of Homeland Security.

A report by CBS News has revealed that at least 305 TSA employees have left the agency since the DHS was shut down in February, serving to further worsen airport security lines.

In addition, documents and internal TSA statistics obtained by CBS News revealed that unscheduled absences among security staff have more than doubled since the shutdown began.

Prior to the shutdown, an average of only 2% of frontline TSA agents would be off on unscheduled absences per day. Now, that number is sitting around 6%.

This is largely because around 50,000 TSA employees are currently being forced to work without pay while the Trump administration faces off with the Democrats over immigration enforcement.

Officials within the TSA are reportedly nervous that the situation will get worse if the shutdown carries on, as more employees opt to leave or stay home.

On Sunday, Houston's Hobby Airport saw 53% of its security staff fail to turn up, leading to 3.5-hour delays at security.

Senate Minority Leader Chuck Schumer on Tuesday said that the Democrats will continue to withhold DHS funding until the administration agrees to reform US Immigration and Customs Enforcement.

In a statement to CBS, a DHS spokesperson blamed the Democrats for the fact that TSA employees were working without pay "for the THIRD time in nearly six months."

"The longer this shutdown drags on, the more financial hardship our patriotic officers and their families face," the spokesperson said. "It's time for Democrats to end these political games."