11/05/2013 01:43 EST | Updated 01/23/2014 06:58 EST

Harper, Mulcair to face off over Senate expenses in question period

Prime Minister Stephen Harper and NDP Leader Tom Mulcair will face off in question period for the third week in a row, this time amid news the RCMP are looking for a chain of emails and documents that support Mike Duffy's allegations the Senate expenses scandal reaches into the Prime Minister's Office. will carry question period live.

CBC News reported on Monday that the RCMP believe "the existence of such documentation may potentially be evidence of criminal wrongdoing by others."

The Nov. 1 letter by Supt. Biage Carrese from the RCMP National Division was obtained by CBC News on Monday and subsequently released publicly by Duffy on Tuesday.

Of particular interest to the Mounties are Duffy's allegations in the Senate last week that his initial story about repaying his disputed expenses by taking out an RBC loan was fabricated by senior advisers to the prime minister.

"Emails from the PMO specifically relating to a script for Senator Duffy to follow in advance of obtaining funds from a RBC loan to repay the Receiver General" may be material to the RCMP's investigation, Carrese said in the letter.

A spokesperson for Harper said the PMO is working with the RCMP.

"We have received no such letter from the RCMP. As we have already stated, we are actively assisting the RCMP in their investigation," Jason MacDonald said in an email.