05/16/2013 02:20 EDT | Updated 07/16/2013 05:12 EDT

A look at key dates in the evolution of the Senate expense-claim controversy

OTTAWA - June 13, 2012: Auditor General Michael Ferguson releases a study of Senate expense claims; in some cases Senate administration didn't have the right documents to support claims travel and living expenses.

Nov. 21, 2012: Senate committee asked to examine housing allowance for Conservative Sen. Patrick Brazeau, who lists a home in Maniwaki, Que., as his primary residence despite appearing to live full-time within a 100 kilometre radius of Ottawa.

Dec. 3, 2012: Similar questions raised about Conservative Sen. Mike Duffy, who claims a primary residence in P.E.I. despite being a longtime Ottawa resident.

Dec. 6, 2012: The Senate widens its audit of housing expenses to include Liberal Sen. Mac Harb, who claims a home near Pembroke, Ont., as his primary residence, and begins examining residence claims of all senators, who are constitutionally bound to live in the provinces they represent.

Feb. 5: Reports emerge that Duffy applied for a P.E.I. health card in December 2012 and that he does not receive a resident tax credit for his home on the island.

Feb. 8: Senate hires external auditing firm to review Brazeau, Duffy and Harb's claims.

Feb. 22: Claiming confusion with the rules, Duffy pledges to pay back claimed housing expenses. "My wife and I discussed it and we decided that in order to turn the page to put all of this behind us, we are going to voluntarily pay back my living expenses related to the house we have in Ottawa."

Feb. 27: Prime Minister Stephen Harper says all senators meet the requirement that they live in the area they were appointed to represent.

Feb. 28: Senate audit fails to turn up any questionable housing allowance claims beyond those of Brazeau, Harb and Duffy.

Apr. 19: Duffy confirms he has repaid more than $90,000 in Senate housing expenses. "I have always said that I am a man of my word. In keeping with the commitment I made to Canadians, I can confirm that I repaid these expenses in March 2013.''

May 9: Senate releases report into housing claims, along with Deloitte audit. Deloitte says a three senators live in Ottawa area, but that the rules and guidelines are unclear, making it difficult to say categorically that anyone broke the rules. Harb and Brazeau are ordered to repay $51,000 and $48,000, respectively. Harb says he will fight the decision.

May 10: Conservative House leader Peter Van Loan on Duffy: "He showed the kind of leadership that we would like to see from Liberal Sen. Mac Harb, who instead is taking up arms against the Senate, saying that he should not have to pay back inappropriate funds."

May 12: RCMP says it will examine Senate expense claims.

May 14: Brazeau says he also broke no rules and is exploring all options to overturn an order to pay the money back.

May 15: The Prime Minister's Office confirms that Stephen Harper's chief of staff, Nigel Wright, personally footed the bill for Duffy's housing expenses because Duffy couldn't make a timely payment.

May 16: Mike Duffy resigns from Conservative caucus to sit as an Independent Senator amid the furor over housing allowances.