Lawyers representing the Senate will soon ask an Ontario court to remove it from a multimillion-dollar lawsuit launched by Sen. Mike Duffy, arguing its actions in the expenses scandal are protected by parliamentary privilege.

A Senate spokesperson told CBC News on Wednesday that lawyers for the Red Chamber will make such an argument in court this week as it looks to extricate itself from a lawsuit the P.E.I. senator launched in August.

In the lawsuit, he asserts his Charter rights were breached by both the Senate and the RCMP.

He claims the Senate's move to suspend him from the chamber without pay at the height of the scandal — and refer his case to the police — was done without due process, subjecting him to "cruel and unusual punishment." Duffy also claims he has suffered serious "stress and serious financial damage" as a result of the Senate's actions.

The Senate spokesperson said members of the Red Chamber were well within their rights as parliamentarians to pursue this course of disciplinary action.

"The Senate's motion will assert that the Senate's actions respecting Senator Duffy's suspension were all protected by parliamentary privilege and therefore, the courts cannot consequently examine the exercise of a privilege and find the Senate liable for these actions," the spokesperson said in an emailed statement.

The Senate maintains parliamentary privilege gives "the level of autonomy required to enable them ... to do their legislative and deliberative work with dignity and efficiency. It is one of the ways in which the fundamental constitutional separation of powers is respected. Parliamentary privilege includes the right for a legislative assembly to control its own proceedings free from outside interference and its disciplinary authority over its members."

The Senate's motion is to be heard on June 27 and 28 in Ottawa.

If the court finds in favour of the Senate, Duffy will have to restrict his legal action to the RCMP.

But Duffy's lawyer, Lawrence Greenspon, told CBC News that he will challenge the claim of privilege — leading to the potential for some courtroom squabbling over the limits of this legal principle, which was designed to grant legal immunity to legislators.

"Privilege protects parliamentarians when they are making laws. But in this case, CIBA, the Senate's Board of Internal Economy, was not considering legislation. It was punishing a senator. The doctrine of privilege was not intended to deny Sen. Duffy or any Canadian due process or the protection of the Charter."

Carissima Mathen, an associate professor of constitutional law at the University of Ottawa, told CBC News in August that it would be "precedent setting" for any court to tell the Senate it was outside of its constitutional authority to suspend Duffy without pay or privileges.

"I would find it strange that the Senate wouldn't have the power to a suspend a member no matter what the circumstances," Mathen said. "Is it really appropriate for the judicial branch to regulate parliamentary activity in this way?"

Duffy is accusing the RCMP of negligence in their investigation of his housing and travel expenses because they did not give him an opportunity to adequately respond to accusations against him before filing criminal charges.

Duffy's suit, filed in an Ottawa court in August, seeks $6.5 million in general damages, $300,000 for loss of income and benefits and $1 million in punitive damages relating to the treatment he faced during the scandal.

An Ontario judge dismissed all 31 criminal charges relating to Duffy's expenses in April 2016, clearing the way for his return to the Senate. Duffy now sits as a member of the Independent Senators Group (ISG).