Preston Manning, a long-time proponent of Senate reform, says that if the federal Liberal Party is determined to change how the upper chamber operates, it should table legislation to that effect.

“The Liberals have never produced a Senate reform bill. And if they’re serious about it, why don’t they?” Manning told CBC News on Wednesday.

“A law-making body actually accomplishes things by passing bills, not by press statement, not by platform statements,” he said. “So if they’ve got some substantive way of fixing the Senate, put it into a bill and compete with the government’s bill. Maybe they’ll do that, but they’ve had 140 years to do so and have not yet done so.”

Manning made the comments hours after Liberal Leader Justin Trudeau expelled all 32 Liberal members of the Senate from his caucus, saying they will now sit as Independents who will have no formal ties to the party.

“I think people will be watching to see if it makes any difference,” Manning said of Trudeau’s decision. “It’ll be interesting to see if these senators, which are professedly Independent, but if they vote together … are they not a de facto political party?”

Manning is part of a project in which Canadians can vote on the future of the Senate, which has been dogged by a spending scandal for more than a year. Canada's auditor general has been called in to audit the Senate's spending, including the expenses of all Senators.

The Conservative government has asked the Supreme Court of Canada what it would take to reform or abolish the Senate.

The Conservatives argue they don't need the provinces to sign off on their Senate reform proposals, while outright abolition would require the approval of at least seven provinces representing 50 per cent of the population.

But most of the provinces and territories disagree with the government's arguments.

With files from The Canadian Press