The country's largest federal worker union says language aimed at boosting accountability at the troubled Department of Veterans Affairs is actually an "assault" on federal employee rights, and asked senators on Monday night to drop it.

The Senate has been working for weeks on new VA legislation, and may introduce a bipartisan plan this week. House Republicans in particular are pushing for language that would make it easier for the VA to fire corrupt or negligent employees.

But on Monday, the American Federation of Government Employees wrote senators to say that language would violate the due process rights and even the civil rights of federal workers.

"Title I of the bill, entitled 'Personnel and Accountability Matters,' is a frontal assault on federal employee due process rights," AFGE wrote.

AFGE noted that the language as currently written would allow the VA to keep employees on staff an an "at will" status, allow the firing process to be sped up, and allow minor reprimands to be maintained in an employee's file.

"The rights of federal employees to defend themselves against accusations of poor performance or misconduct are matters of civil rights as well as due process rights, and AFGE will stand firm in defense of those rights," the letter said.

The union also said the bill would end up hurting women and minority workers more than others, although it didn't say how.

AFGE argued that scaling back these due process rights would turn federal employment into a political "spoils system" that would let parties stock the government with people they like, and deprive deserving workers of their jobs.

"A professional, nonpartisan civil service system is vital to the American people because it ensures that hiring is based on competency instead of political patronage or other non-merit factors, including race," the letter said. "Surely veterans deserve no less for their health care system."

The group also argued that the legislation under consideration would only advance "the Koch brothers' privatization agenda."

Congress passed legislation in 2014 that allows the VA to quickly fire senior VA officials. But the VA has been loathe to use the law, and after nearly two years, only a small handful of VA workers have been fired under that law.

Just last week, the VA announced it was seeking to discipline two other senior officials, but chose not to use the 2014 law. Instead, the VA is using another law that gives federal workers much more leeway and warning.

Partly in response to that track record, the House has passed legislation in the current Congress to speed up the process of firing non-senior officials at the VA. But some in the House suspect the Senate won't include that provision in the bill they introduce, and AFGE's letter shows there is pressure from federal workers to make sure it's not included.