Two key lawmakers warned Thursday that the failure of Congress to pass new language allowing the Department of Veterans Affairs to fire corrupt or negligent officials would be a "disservice" to the nation's veterans.

Sen. Marco Rubio, the recent presidential candidate, and Rep. Jeff Miller, who chairs the House Veterans' Affairs Committee, wrote to the chair of the Senate VA Committee to urge him to consider Miller's bill, which would expand the VA's authority to fire officials.

Miller's language passed the House easily last year, and was also approved by Sen. Johnny Isakson, R-Ga. Miller and Rubio said they fear that while early talks might have led to the inclusion of Miller's bill into a broader VA package of legislation, it might now be at risk of being ignored.

"[W]e are now concerned that you have halted the aforementioned negotiations and may be taking an approach that favors reaching a deal with the administration or others at any cost, regardless of whether it actually addresses the VA's many problems or pays for new programs in a responsible way," they wrote.

"We hope you realize that any piece of comprehensive veterans' legislation that doesn't provide the VA secretary swift and comprehensive disciplinary authority for all VA employees misses the true mark on what ails the department," they added. "Not including such strong accountability language would be a disservice to both taxpayers and our nation's veterans."

Miller has argued repeatedly that the need to fire VA workers has become clear over the last year, since the VA has barely used its new authority to fire or discipline senior employees involved in the healthcare scandal that broke in 2014. The VA has fired just a few workers for that scandal, and Miller says it's time to expand that authority to all VA employees, not just senior-level workers.

The letter noted that most recently, the VA wasn't able to fire an employee in Puerto Rico who "participated in an armed robbery."

"This is only the latest example in what is a steady cascade of real-life examples demonstrating the outright dysfunction of the civil service rules governing the VA," they wrote.

"Almost every day Americans are reminded that the federal civil service system is designed to coddle and protect corrupt and incompetent bureaucrats rather than facilitate a fair and efficient climate of accountability," Miller added in a separate statement Thursday. "Nowhere is this more visible than the Department of Veterans Affairs."

As of this week, it's unclear whether Miller's language will make it into the larger VA bill the Senate is hoping to pull together. Amanda Maddox, a spokeswoman for Isakson, told the Washington Examiner that a bill should be forthcoming in April, but that its exact contents aren't settled.

"We are ironing out last minute details and are looking at introducing in the next week or two," she said.

Efforts to write a tough VA bill have fallen apart before. In 2014, for example, the House passed legislation giving the VA secretary more of a right to simply fire officials who aren't doing the job of helping veterans. But that language got watered down when it reached the Senate, in large part because of Sen. Bernie Sanders, I-Vt., who chaired Isakson's committee then.

Specifically, Sanders included language giving employees the right to appeal decisions that they be fired or disciplined.

Read the Rubio/Miller letter here: