It has absolutely zero chance of passing.

But, on Tuesday, the Liberals will introduce a motion in Parliament to compel Stephen Harper to testify — under oath — about what he knows with regard to Nigel Wright's $90,000 cheque to repay Senator Mike Duffy's housing allowance.

Here's the Opposition Day motion to be introduced by Deputy Liberal Leader Ralph Goodale:

That the Standing Committee on Access to Information, Privacy and Ethics be instructed to examine the conduct of the Prime Minister’s Office regarding the repayment of Senator Mike Duffy’s expenses; that the Prime Minister be ordered to appear under oath as a witness before the Committee for a period of 3 hours, before December 10, 2013; and that the proceedings be televised.

Again, the non-binding motion, which will be debated, is not going to pass with a majority Harper government.

But it's another means for the opposition to score some points with an increasingly cynical public frustrated with senate expense controversies and scandals.

And, you have to believe that most Canadians would want to see Harper under oath. A Nanos Research survey released last week suggests that only 21 per cent of Canadians are satisfied with Harper's explanation about the Wright/Duffy affair.

[ Related: Trudeau challenges Harper to testify under oath ]

Meanwhile, the Tories continue to try and 'change the channel.'

Unfortunately, for them, they're not having a lot of luck in that regard.

During Question Period, on Monday, the opposition focused on a peculiar comment made by Senator Irving Gerstein at the Conservative Party policy convention over the weekend.

During his speech, Gerstein — who is charge of the Conservative Party's fundraising arm — said that he told Wright that the Party wouldn't pay for Duffy’s expenses and never did. That, however, seems to contradict Wright's testimony to the RCMP.

"Nigel Wright told the RCMP that the Conservative party initially offered to repay the expenses of Mike Duffy. This weekend Irving Gerstein claimed that this was not the case," deputy NDP leader Megan Leslie said in the House.

"Which version of the story does the parliamentary secretary believe. Wright's story or Gerstein's story? Which is it?"

[ Related: Crisis communications expert offers advice for Stephen Harper and Rob Ford ]

In the other chamber, senators voted to invoke closure on the debate of a motion to suspend Senators Duffy, Wallin and Brazeau without pay but with benefits.

A vote on the suspensions is expected to happen at 5:30pm (EST) on Tuesday.

(Photo courtesy of the Canadian Press)

Are you a politics junkie?

Follow @politicalpoints on Twitter!