NDP Leader Tom Mulcair is urging "free-thinking" Conservative MPs to vote against the government's proposed changes to how Canadian elections are run.

Mulcair said there are Conservatives who talk about parliamentary reform, and he wants to see them follow those words with a vote against the proposed changes to Canada's Elections Act.

"Our message to the Conservatives who talk a lot about the importance of our democratic institutions is it's time to walk the talk. It's time to show that you actually do care, because this bill [C-23] still contains several things that are profoundly anti-democratic," Mulcair said in the foyer of the House of Commons.

Minister of State for Democratic Reform Pierre Poilievre made a number of major amendments to the bill last month and argued the changes make a terrific bill even better.

But the changes didn't go far enough, the NDP say.

"The bill is a travesty. The Canada Elections Act as it stands is a far better bill" than what the law will be if C-23 passes, said NDP reform critic Craig Scott.

Vote Monday night

The NDP is also asking Conservative whip John Duncan to allow a free vote on the fair elections act.

In an interview with CBC News, Duncan said he expected all Conservatives MPs would vote to pass the bill.

"Any member that wishes to vote otherwise will let me know, but it's not anticipated that we will have anyone not supporting this major government bill," he said.

So far, no Conservative MPs have taken up the NDP's request they vote against it.

The Conservatives have the majority in the House and the Senate, so the bill is expected to pass unless some Conservative MPs and senators vote against it.

After nearly two hours of back-to-back votes, the bill made it through report stage on Monday night.

A final Commons vote will be held on Tuesday evening, at which point it will be sent to the Senate.