Liberal Leader Justin Trudeau told CBC News on Wednesday that his surprise decision to expel all his party's members in the scandal-plagued Senate from the Liberal caucus has nothing to do with an impending auditor general's report.

"I know absolutely nothing" about the report, Trudeau said in an interview with CBC chief correspondent Peter Mansbridge that aired on The National.

Trudeau had announced Wednesday morning that the former Liberal senators will sit as Independents, and they will have no formal ties to the Liberal parliamentary machinery except through friendships.

Auditor General Michael Ferguson is currently reviewing the Senate's spending, leading the Conservatives to suggest Trudeau's move is meant to distance the party from Ferguson's findings.

Trudeau acknowledged transparency and accountability over expenses are hurdles the Senate must overcome, but said his decision is not about those problems.

“It’s a separate problem from the excessive partisanship and patronage in the Senate, which is what I have moved to eliminate today.”

He said his decision came today rather than if he is elected as Canada's next prime minister because "it's never the wrong time to do the right thing."

Trudeau told Mansbridge he made the change to show the Senate could be made better without reopening the Constitution.

Trudeau said removing the Senators from his caucus will change the conditions under which they consider legislation because they will not have to worry about the political implications on their party.

This is a first step in improving the "partisanship and partisan interference" in the Senate, he said.

Watch the complete interview in the video above.