From the outset, Mike Duffy and Pamela Wallin were different.
Well-known TV journalists, they stood out in the group of 18 new senators – many of whom were former party fundraisers, politicians or failed candidates – appointed en masse by Prime Minister Stephen Harper in 2008.
Rather than a soft-landing near retirement, the Senate was a second life for Ms. Wallin and Mr. Duffy. And both quickly emerged as stalwarts on the campaign trail and the fundraising circuit, staunch partisan voices who commanded attention. They frequently travelled to party-related events, bringing clout, big-name recognition and charm in a way others could not. Conservative associations across the country advertised gala events with Ms. Wallin and "Old Duff" as headliners. They were stars.
Now, both are at the centre of a growing controversy over expenses in the Red Chamber. Ms. Wallin's travel claims are under review, while Mr. Duffy's repayment of tens of thousands of dollars in housing expenses is under renewed scrutiny after it was revealed the Prime Minister's top aide wrote Mr. Duffy a cheque for more than $90,000.
Through interviews with members of riding associations, MPs and senators, and a review of Elections Canada returns and other records, a picture emerges of two former on-air hosts who became top voices for the party and the Prime Minister.
"We won the  election, and I'm sure Mike [Duffy] was very instrumental in that," fellow Conservative senator and friend Don Plett says. "… He was a huge asset to us."
But questions emerged about both senators' expenses after the election. The Globe and Mail found seven instances in which Mr. Duffy appears to have billed per diems to the Senate on days when he was campaigning for Conservative candidates. Mr. Duffy's audit, which initially focused on whether he was entitled to a housing allowance for his home in Ottawa, was returned to a Senate committee for further review after questions about his campaign expenses were raised in the media.
Ms. Wallin, meanwhile, had commitments outside the Senate and, according to a source familiar with her ongoing audit, frequently switched flights or booked them at the last minute, driving up costs. Her audit is focused on travel expenses. It was limited at first to a recent 18-month period, but members of the Senate committee asked auditors to cover an additional year of her time as a Senator after hearing a progress report last month.
ON THE HUSTINGS
The 2011 federal election allowed both senators to lend their profiles to local Conservatives. Ms. Wallin campaigned in her home province of Saskatchewan and made at least one trip to Simcoe-Grey, a riding north of Toronto where Conservative Kellie Leitch faced embattled former Tory Helena Guergis. Ms. Leitch declined an invitation to an all-candidates' forum so she could campaign with Ms. Wallin, according to local newspaper reports.
Mr. Duffy – who had built a reputation as an active public speaker and Conservative Party fundraiser – campaigned with 17 Conservative candidates during the writ period, including Mr. Harper, according to returns filed with Elections Canada. He hit ridings on the east coast, and spent time in Toronto and the Northwest Territories.
But some of Mr. Duffy's stops are being questioned since it was revealed that he appears to have claimed per diems for Senate business on days he was on the hustings. The allegation that he may have been "double dipping" – billing both the campaigns and the Senate for the trips – prompted the Senate to send his audit back to the committee that handled it for further review.
Those days include April 5 to 7, when Elections Canada records show he was with the Prime Minister in Toronto during the campaign but also claimed to be on Senate business; April 8, when he joined a campaign in the Northwest Territories and claimed to be on Senate business; April 21, when Elections Canada records show he campaigned in Nova Scotia but the audit says he claimed a per diem in Ottawa; and April 27 and 28, when he visited eight campaigns in Toronto just before the vote, with the audit showing he claimed those days as Senate business.
Expenses from trips to Atlantic Canada and Toronto were meant to be split among the candidates Mr. Duffy visited, Elections Canada records indicate, but not all of them reported Mr. Duffy's claims.
Mr. Duffy charged his travel costs to individual campaigns, surprising some campaign workers. His expenses included airline tickets (one executive class, one economy), rental of a Jeep Liberty, gas, cab trips and hotel rooms. He also campaigned in the Ontario election. On Sept. 8, 2011, when the Senate was not in session, the PEI senator attended an Ottawa party event while claiming, on the same day, a per diem for Senate business in the city.
After the election, his party-related efforts continued. Mr. Duffy spoke at a $100-a-plate fundraiser in Delhi, Ont., with Senator Doug Finley and his wife, Human Resources Minister Diane Finley, in 2012. On the same day, he claimed a Senate per diem saying he was on "other business" outside Ottawa.
Mr. Plett, who calls Mr. Duffy "one of the harder-working senators that we have on the Hill," said he does not know anything about Mr. Duffy's expense claims while campaigning. "There most certainly should not be any double dipping, charging through the party and then charging through the Senate," he said.
Mr. Duffy has repeatedly refused to comment when contacted by The Globe. However, he told reporters on Thursday in Ottawa he wants a "full and open inquiry" into his expenses.
Ms. Wallin says she campaigned during an 11-day period in 2011 in Saskatchewan, but declined to say where. One of her speeches was in Moose Jaw, in MP Ray Boughen's riding. According to audio posted by a local news agency, Ms. Wallin prefaced her speech by saying, "You're going to hear a pretty partisan set of comments."
Gilles Duceppe makes her "twitch" and NDP leader Jack Layton did not want an election because "his wife [MP Olivia Chow] doesn't qualify for her parliamentary pension yet," Ms. Wallin told the crowd. E-mails filed as part of elections returns show Ms. Wallin, at the request of the campaign, billed it for a hotel room, two days' car rental and an $85 per diem. There is nothing to indicate Ms. Wallin billed the Senate for her expenses on days she was at campaign events.
It is common for senators to attend rallies for friends or nearby candidates. But the idea does not sit well with all members.
"I have not sponsored any function … that's my particular choice. I'm not saying that others cannot do that. I think that has to be clear. I just personally have not done that," said Raynell Andreychuk, a Conservative senator from Saskatchewan who was appointed by Brian Mulroney and is chair of the Senate's Conflict of Interest Committee.
Ms. Wallin attended other events outside the election period. Later that year, she campaigned for Brad Wall's Saskatchewan Party, which has close ties with Mr. Harper's Conservatives. And she attended a $100-a-plate fundraiser in MP Garry Breitkreuz's Saskatchewan riding in January, 2011.
"She's very well-known. That was why we wanted to have her come. We knew she'd be a good drawing-card," said Beth Berg, who helped organize the 2011 fundraiser.
Now, many are disappointed that Senate expenses are in the news. "If there's fault, I guess it needs to be found out about. The persons themselves, they're above reproach in my own personal opinion," Ms. Berg says.
Mr. Wall, Saskatchewan's Premier, declined to comment on Ms. Wallin, who now sits as an independent.
The storm over Senate expenses began to develop late last year, when questions were raised about whether senators from outside the National Capital Region who spend most of their time in Ottawa should get a housing allowance worth up to $22,000 per year for accommodation in the capital.
Mr. Duffy represents Prince Edward Island but has lived and worked in Ottawa for decades. His housing allowance claims were sent to auditors for further review, along with those of Mac Harb, a Senator who recently left the Liberal caucus, and Patrick Brazeau, who was kicked out of the Conservative caucus.
When Ms. Wallin confirmed that she, too, was facing an audit, the issue of her travel expenses erupted in the House of Commons.
"Senator Wallin is using taxpayers' money to travel around the country and to star in the Conservative Party's fundraising activities," NDP Leader Thomas Mulcair charged. Mr. Harper defended Ms. Wallin, saying her costs are "comparable to any parliamentarian."
Ms. Wallin's expenses initially raised concern because only a fraction of her bills were listed as "regular travel," the Senate's term for trips between a senator's primary residence and the National Capital Region. She said earlier this year that many of her flights to Saskatchewan are not direct, and are therefore listed as "other travel" on her expense forms. But questions have been raised about whether some trips include travel that is unrelated to her Senate duties, and therefore should not have been claimed.
Ms. Wallin has repaid some of the money she claimed since becoming a senator in early 2009, including about $25,000 immediately before her audit began, according to sources familiar with the expense review.
A disclosure form filed with the Senate Ethics Officer indicates Ms. Wallin is paid at least $2,000 a year for her roles on three different boards. She sits on the boards of Porter Airlines, Gluskin Sheff & Associates, and an organization called the Ideas Council. The Globe and Mail searched corporation records and charity filings in Canada and could not find an organization with the latter name. Ms. Wallin declined to say what the council is or how much it was paying her.
"All further comment on these issues will be forthcoming as soon as the audit is complete. We are working with the auditors to provide all information and as soon as their report is concluded, I look forward to answering any and all questions," Ms. Wallin said in a written statement.
Ms. Wallin has continued her work inside and outside the Senate. An honorary colonel of the Royal Canadian Air Force, she took part in a cadet ceremony this month in Swift Current.
"I thought she did a great job," said Jeff Kurtz, one of the parents involved in the local air cadets. "I thought it was quite passionate and motivational."
NDP ethics critic Charlie Angus says Ms. Wallin and Mr. Duffy pushed the limits on campaigning and sparked the firestorm.
"It allowed them the extra men on the ice during campaigns. It allowed them to be full-time partisan workers aided by the taxpayer. … It just seems that it's Stephen Harper who takes everything to the absolute limit. And they eventually killed their golden goose."