A day before an extensive report on Senate spending is to be publicly released, two of the red chamber’s most prominent members have committed to repaying the expenses flagged by the auditor general.

Michael Ferguson’s report will name 30 former and sitting senators who allegedly owe money, including Conservative-appointed Senate Speaker Leo Housakos and Liberal-appointed Opposition Leader James Cowan.

Both men said last week they planned to appeal to a special arbitrator appointed to deal with questionable expenses, but they appeared to reverse their positions on Monday.

“I do not wish there to be any question surrounding the integrity of the process or the manner in which it was implemented,” Housakos said in a statement. He has been told to repay $6,770.

Opposition Leader James Cowan also said Monday he has repaid $10,397 in disputed expenses, despite standing by his position that “all expenses charged by me to the Senate were, and will continue to be, entirely appropriate.”

“While I categorically deny such allegations, I have concluded that pursuing my right to arbitration, which I had intended to do, would cast a shadow in some minds over the fairness and independence of the process itself,” Cowan said.

The 30 senators named in the report are said to collectively owe nearly $1 million in allegedly inappropriate expenses. Two other senators -- Nicole Eaton and Claude Carignan -- have already paid back the money allegedly owed, while four others have repaid portions.

Five senators -- Rod Zimmer, Marie Charette-Poulin, Rose-Marie Losier-Cool, Sandra Lovelace Nicholas and Pierre-Huges Boisvenu -- account for more than half of the amount alleged to be owing: $553,731.

Four of these cases are among nine the Senate Speaker has referred to the RCMP for criminal investigation. Lovelace Nicholas is among the other 21 senators whose cases will not be sent to the Mounties, and will instead be dealt with through an arbitration process.

Boisvenu left the Conservative caucus last week to sit as an Independent.

Can the Senate be changed?

On the eve of the report’s release, NDP ethics critic Charlie Angus reiterated his party’s long-held position that the Senate should be abolished.

“I don’t think Canadians have any reason to put faith in them,” Angus said Monday.

Speaking to reporters at the G7 summit in Germany, Prime Minister Stephen Harper said Canadians have no “appetite for returning to long, drawn-out, sustained constitutional negotiations.”

Harper had long advocated for Senate reform, including terms limits and an electoral process, but changed course after the Supreme Court last year ruled that such changes would require constitutional amendments approved by at least seven provinces representing half of the population.

Gordon Barnhart, a former Clerk of the Senate who is now Interim President of the University of Saskatchewan, told CTV Power Play he has little hope that enough provinces could agree to the constitutional amendments required for Senate reform.

“On the other hand, I do see a solution,” he said. “If the (Board) of Internal Economy sets very clear (rules) and then the Clerk of the Senate was entrusted with enforcing them equally for everybody -- without political interference -- that would solve a lot of the problems.”

Barnhart said part of the problem is that the “job description” of a senator is “hard to define.”

There is “nothing illegal” about doing political work in addition to legislative functions, he said, adding: “That’s the part that now seems to be coming under scrutiny.”

Barnhart called the release of the auditor general’s report a “hard day for all senators” and said “good, hard-working senators” will be “painted with the same brush.”