The Senate has hired an outside auditor to examine the residency declarations and related expenses of three senators, and is also seeking legal advice about the status of Conservative Senator Mike Duffy's residency.

Conservative Senator David Tkachuk, chair of the committee on internal economy, says the Senate may look at changing its own rules about residency and submitting expenses.

One of the problems, he says, is that the constitutional requirement that a senator be a "resident' of the province he or she represents does not define what is meant by the word.

"The constitution is quite nebulous about this. It says residence, it doesn't say primary residence," Tkachuk said in a telephone interview Friday from his residence in Saskatoon.

The Constitution requires that every senator own property and maintain a residence in the province he or she is supposed to represent in the Senate.

Tkackuk also said the Senate is looking to an outside auditor, in this case Deloitte, because the Senate doesn't want to appear as if it is hiding anything by having its own members conduct the probe.

The other two senators are Liberal Mac Harb of Ontario and Quebec's Patrick Brazeau, who has just been criminally charged in a completely separate matter. Brazeau is now sitting as an independent after being kicked out of Conservative caucus Thursday.

'It's a different world'

The three senators have been under fire lately for claiming expenses for residences outside Ottawa even though they own or rent homes, in some cases doing so for years, in the capital.

Duffy, although he claims a cottage in P.E.I. is his residence, doesn't pay income tax in the province and only applied for a new P.E.I. health card following media stories that detailed how he has owned his home in Ottawa well before he was appointed to the Senate.

Harb, a former Ottawa MP and now an Ontario senator, claims his residence is actually in Pembroke, 100 kilometres from Ottawa, where he has a house.

Brazeau, now facing assault charges in a separate incident, has been claiming his father's home in Maniwaki, Que. — again more than 100 kilometres from Ottawa — as his residence, even though he lives in a house in Gatineau, just across the river from the capital.

All three senators have been claiming expenses for living in Ottawa, or in Brazeau's case, in Gatineau, a virtual stone's throw from Parliament.

Tkachuk explained the rules were changed in the '90s so that senators could submit expenses for a house or a condo which he said, "had to be a lot cheaper than a hotel."

He continued, "Even though Mike's [Duffy's] expenses are 30 or 35,000 bucks [since his 2009 appointment], they're only $10,000 a year, which is a lot cheaper than I spend — I stay in a hotel. So they have a small subsidy for buying a house, because some people are older, they have health problems, they can't fly back every week."

Tkachuk said the subsidy for a house or condo in Ottawa amounts to $900 a month, and it's meant to substitute for hotel costs. He assumes this is what Duffy has been collecting.

Tkachuk didn't seem to have a problem with Duffy's expense claim, and explained that Duffy visits P.E.I. frequently and has a residence there. "Whether he closes the place up for the winter... If I was Mike I wouldn't be travelling back and forth either, because his heart condition is not that great. I wouldn't be getting on a plane, trying to get to Charlottetown every week."

Retired senator Lowell Murray, who was appointed by Joe Clark's Progressive Conservative government, said in an interview airing Saturday on CBC Radio's The House, "Senator Duffy's problem is not just an ethical problem potentially and a problem with the Senate rules. Potentially, his problem is a serious constitutional problem because if it can be demonstrated he is not a resident in Prince Edward Island, then he's finished, he's a goner, he's been sitting while he's disqualified. "

Duffy does not pay the resident-only property tax for his house in P.E.I., but instead pays a special tax for non-residents. But Tkachuk said, "P.E.I. says he's not a resident. Well, as far as I'm concerned, those are the provincial provisions of residency, they have nothing to do with the Constitution."

Tkachuk admits he's not happy about the negative publicity the Senate has been getting lately, and added, "Our intent is not to hide anything."

He went on to say, "It's a different world — rules that made sense a long time ago don't necessarily make sense today."

A legal or moral issue?

Al Rosen, a Toronto investigative accountant, said in an interview that it's difficult to know whether Duffy's and the other senators' residency is a legal or a moral issue. He thinks Duffy has possibly found a loophole in the rules.

"The real problem is the definition of residency ... the definition has to exist. You can't just say just because he [Duffy,for instance] only has three plane tickets going to P.E.I., there's something wrong, that he doesn't meet the definition that doesn't exit. So the defintion has to exist," Rosen said.

Talking to reporters Friday, NDP MP Alexandre Boulerice said he thinks the expenses issue "will convince Canadians that maybe the Senate is a bad institution and it’s costly and it’s not working anymore."

The NDP advocates that the Senate be abolished.

Liberal MP Rodger Cuzner dodged the question of whether the Senate should be done away with.

"You know, we’re looking at a government that, that bodes, you know, prides itself in law and order and playing by the rules and accountability and transparency and one of their own seems to be, you know, taking such a flagrant abuse of, of the rules," he said.

Prime Minister Stephen Harper, speaking to reporters in Vancouver where he made an announcement about crime, admitted there were "a couple of cases that are extremely difficult" when asked about his Senate appointments. Harper appointed both Duffy and Brazeau.

Harper said he would prefer if provinces would hold elections for senators, as Alberta has. "I have appointed those elected people. And that's the reform we'd like to continue to see move forward, along with defined and shortened mandates," he said.