Senate lawyers have asked a federal judge to dismiss a lawsuit against Sen. Mark Dayton filed by a former aide who alleges that the Minnesota Democrat abruptly fired him after learning that the aide required heart surgery.

The case is the latest test of the limits of the 1995 Congressional Accountability Act, which purportedly extended coverage of 11 workplace and safety laws to Congressional workers, with enforcement through litigation and judicial review. Ironically, employment lawyers for the Senate, which overwhelmingly approved the touted reform measure, have consistently moved to curtail the law by arguing that the Constitution’s legislative privilege shields lawmakers from employment-related litigation.

In a May 29 complaint filed with the U.S. District Court for the District of Columbia, Brad Hanson, an aide who was responsible for establishing a health care constituent hotline for Dayton’s Minnesota-based Senate offices, alleged that Dayton violated the Family and Medical Leave Act and the Americans with Disabilities Act and failed to pay him overtime compensation in violation of the Fair Labor Standards Act. Dayton has denied the allegations.

According to the complaint, Hanson, who had worked for Dayton’s campaign before joining the Senate payroll, developed cardiac arrhythmia in early 2002 and was told by a doctor that he would need surgery that would require a recovery period of two to three weeks.

Hanson, who informed others in Dayton’s Ft. Snelling, Minn., office of his condition, scheduled a meeting to personally inform Dayton. A July 3 meeting with Dayton, the complaint said, “had not gone on for more than five minutes when the Senator abruptly told Hanson, ‘You’re done.’ He did not explain why. A short time later, Senator Dayton informed the staff in the Ft. Snelling office that Hanson was leaving. Again, he gave no explanation,” the complaint alleged.

At the same meeting, according to the complaint, Dayton told Hanson that he should no longer report to the office but should instead go on medical leave. On July 17, an aide in Dayton’s Washington office called Hanson at home and informed him that he would be terminated as of Sept. 30.

Richard Salzman, Hanson’s Washington, D.C.-based attorney, did not return several phone messages, and Hanson could not be reached for comment.

“It’s not true and we filed a motion to dismiss,” said Chris Lisi, a spokeswoman for Dayton. She referred questions to Jean Manning, the Senate’s employment legal counsel.

Manning filed a formal response to the lawsuit last week, arguing that U.S. District Judge Richard Leon should dismiss the case because the Constitution’s Speech or Debate Clause protects lawmakers from litigation that would allow the courts to look at the operations of a legislative office. Her brief focused entirely on procedural and jurisdictional issues without directly addressing Hanson’s allegations.

The argument nearly mirrored the position Manning took in a 2001 case involving an age discrimination claim filed by a former aide to Sen. Ben Nighthorse Campbell (R-Colo). Rita Bastien, the plaintiff in that suit, has appealed a ruling by a Wyoming judge who dismissed her suit and ruled that even an aide remotely connected to the legislative process would be barred from bringing suit by the constitutional privilege.

Echoing a line of reasoning made in the Bastien case, Manning said that Hanson acted as Dayton’s “eyes and ears” in providing constituent feedback that was used to develop legislative proposals. Hanson, the brief said, played a leading role in helping Dayton write legislation dealing with Medicare reimbursement for ambulance service and noted that he was instrumental in planning and conducting a hearing chaired by Dayton.

The Speech or Debate Clause states, in part, that “for any Speech or Debate in either House, [Members of Congress] shall not be questioned in any other Place.” It is a jealously guarded shield affording true legislative independence from coercion with deep historical roots reaching back to the struggles between crown and Parliament.

But the essential immediate question in recent cases involving employment and personnel matters is how far the privilege goes. Supporters of the Congressional Accountability Act say that Congress meant to subject itself to the same types of workplace laws that govern every other employer and that the privilege should not be used to stop that process.

But in her brief, Manning contended that “personnel actions taken against employees whose job duties directly relate to the due functioning of the legislative process are legislative acts for which the Speech Or Debate Clause provides absolute immunity.”

The brief went on to assert that “a Member’s constitutional mandate of handling all legislative matters necessarily includes the authority to fire, without judicial interference, employees whose duties are directly related to the functioning of the legislative process.”

Citing a series of rulings, she wrote, Dayton’s “personnel actions taken with respect to Plaintiff are legislative acts of which this Court has no jurisdiction to question Senator Dayton or his aides, to accept evidence, or to hold Defendant accountable.”