Conservative Senator David Tkachuk has stepped down as chair of the internal economy committee, citing health reasons.
The Senate committee was responsible for ordering a series of controversial audits of four senators' expense claims. Earlier this year, it announced that Senators Mac Harb, Patrick Brazeau and Mike Duffy would have to repay tens of thousands of dollars in claims. A separate audit of Senator Pamela Wallin's travel expenses is still ongoing.
Mr. Tkachuk said he will be receiving treatment for cancer. He said he was stepping back from his role as committee chair to reduce his stress and give the treatment the best chance of succeeding.
"I don't like to leave unfinished, and so this has been a very difficult decision for me to make," Mr. Tkachuk said.
The Saskatchewan senator faced criticism this spring after his committee softened the language of a report on Mr. Duffy's expenses. The committee later restored the original language after it was revealed that Mr. Duffy repaid the Senate using money from the Prime Minister's chief of staff.
Mr. Tkachuk said the process for choosing a new chair would be up to the Senate leadership.
He will remain as chair until the end of the week and will continue to be on the committee once a new chair is chosen.
The committee is scheduled to meet behind closed doors Tuesday evening with the Auditor-General to discuss the scope of a proposed audit of Senate expenses.