Embattled Sen. Mac Harb announced Monday that he is retiring from the Upper Chamber and has repaid all ineligible expense claims from the past eight years, totalling more than $230,000.

In a statement sent to the press by his lawyer, Paul Champ, Harb said he delivered a letter to Gov.-Gen. David Johnston to advise that he will step down from the Senate effective immediately.

“I have been contemplating retirement for some time as I personally never considered the Senate to be a lifetime position,” Harb said in his statement.

“These past few months have been extremely difficult for me and my family and caused me to evaluate what more I could contribute in the circumstances. My dispute with the Senate Committee on Internal Economy made working effectively in the Senate unrealistic.”

Harb was one of four senators caught up in the ongoing expense scandal, in which external audits identified thousands of dollars of ineligible living or travel claims.

When the results of the audits into expenses filed by Harb, Patrick Brazeau and Mike Duffy were released in May, the Senate ordered Harb to repay $51,482.90 in ineligible expenses claimed over an 18-month period.

Sen. David Tkachuk later said Harb in fact owed a total of $231,649 in improperly claimed housing and living expenses dating back to 2005.

Harb first repaid the smaller amount “under protest,” according to an earlier news release, “which means that he vigorously denies any liability” and intended to challenge the order in court. On Monday, Harb signalled that he has dropped that court action.

Harb also said Monday that he has submitted a cheque to the Senate’s internal economy committee for $180,166.17, for a total reimbursement of $231,649.07.

The 59-year-old is retiring well before the age at which he would have to step down if he served out his term: 75. Harb will be eligible to receive his full pension of $122,989 annually right away based on his House and Senate service, according to the Canadian Taxpayers Federation.

In his statement, Harb said his court challenge was never about money. Rather, “The Senate Committee treated me very unfairly, and I wanted to make the point that every Canadian, even Senators, should be entitled to due process. I always followed Senate rules on expenses, and filed my expense claims in a timely and transparent manner. At no time did anyone suggest my claims were invalid or questionable. And from what I could tell, most Senators made similar claims.”

In the statement, Champ said his client’s audit did not find that he violated Senate expenses rules, but instead that the rules “were insufficiently clear.”

Champ alleges that the Senate’s internal economy committee, “rejected the independent Deloitte report and retroactively applied its own vague definition of residence, with criteria that are not set out in any Senate rules or policies.”

The audits, including an audit into the travel expenses of Sen. Pamela Wallin, have since been turned over to the RCMP.

Duffy repaid some $90,000 in improper expenses with the help of a cheque from Nigel Wright, Prime Minister Stephen Harper’s then-chief of staff. Wallin promised to repay the more than $120,000 in travel expenses that were deemed ineligible and had previously repaid an additional $38,000. Brazeau missed an initial repayment deadline on the $48,000 he owes and is now having his senate pay docked.

In his statement, Harb said he welcomed the recent announcement by Auditor General Michael Ferguson to probe all senators’ expenses.

“I have no doubt that the Auditor General’s final report will vindicate me as it will show that many Senators had the same understanding of the rules as I had and made similar expenses claims,” Harb said.

Harb was appointed to the Senate in September, 2003, and before that served for 15 years as Member of Parliament for Ottawa Centre. He also spent three years as a city councillor in Ottawa.

In his letter to Johnston, Harb said he is “proud of what was accomplished” in his 28 years of public service, and thanked his staff and his family.

“It was an honour to be able to serve the people of Canada,” he said.