A view of the Senate chamber on Parliament Hill in Ottawa on Jan. 13, 2011. THE CANADIAN PRESS/Sean Kilpatrick

OTTAWA - Conservative and Liberal leaders in the much-maligned Senate are joining forces to salvage the upper chamber's tarnished reputation.

They are demanding a swift — and public — resolution to allegations that some senators are abusing a housing allowance meant to compensate those who keep a secondary residence in Ottawa.

The Senate's internal economy committee has been investigating the allegations and last week called in an outside auditor to scrutinize three cases — involving Conservatives Mike Duffy and Patrick Brazeau and Liberal Mac Harb.

In a rare show of bi-partisanship, government Senate leader Marjory LeBreton and Liberal Senate leader James Cowan have written the committee urging it to interview senators who have claimed the allowance in order to confirm their claims.

LeBreton and Cowan say that if a claim is found to be invalid, the senator in question should be required to immediately repay the money, with interest.

They say the Senate's reputation is at stake, so it's "vital" that the matter be resolved quickly and transparently.

"We believe it is vital for the reputation of the Senate and those senators who are in full compliance with our rules and regulations that this determination be made as soon as possible and that the results be made public," the letter reads.

The Senate's reputation was further sullied last week when Brazeau was arrested after a domestic incident and charged with assault and sexual assault.

The housing allowance controversy has been bubbling for more than two months, following reports that Brazeau, Duffy and Harb have been collecting the allowance even though their primary residences are in the national capital region.

In addition to calling in external auditors at Deloitte to examine the three senators' residency declarations and expenses, the internal economy committee is seeking legal advice on the question of Duffy's residency.

The controversy has evolved into an even bigger question for Duffy: Is he eligible to sit in the Senate at all?

The Constitution requires that senators reside in the provinces they were appointed to represent. Duffy represents Prince Edward Island and, although he's claimed his cottage on the island as his primary residence, neighbours and provincial records suggest he spends very little time there.

The internal economy committee last month requested that each senator who claims the secondary residence allowance provide proof that their primary residence is not within 100 kilometres of the capital.

Senators were required by the end of last month to produce copies of their health card, driver's licence and income tax return and a declaration as to where they vote in federal, provincial and municipal elections.

In a scramble to meet the deadline, Duffy requested an expedited P.E.I. health card but the provincial government turned him down. Provincial tax records show Duffy and his wife are identified as non-resident owners of their island cottage.

News from © The Canadian Press, 2013