MPs kicked off a debate Tuesday on a proposal to encourage federal parties to run equal numbers of men and women.

If adopted, New Democrat MP Kennedy Stewart's private member's bill, C-237, would penalize political parties that don't come close to gender parity on their candidate slates. The bill will get an hour of debate this week, with another hour to follow likely in the fall.

Women hold only 26 per cent of the seats in the House of Commons -- the best-ever result, but still far from a number that reflects the percentage of Canadians who are female. According to the International Parliamentary Union, Canada ranks 61st in the world in terms of female MPs.

Stewart's proposal would see the parties lose a percentage of their election refunds. Federal parties are eligible to get half of their campaign expenses refunded; his bill would see them lose a portion of that if they didn't achieve 45-per-cent female slates.

Private member's bills are less likely to become law because they don't have the automatic support of a governing party the way government bills do. But Stewart says MPs from each party support his bill, including Liberal MP Pam Damoff, vice-Chair of the status of women committee, Conservative Senator Nancy Ruth and several of his New Democrat colleagues.

The amount each party would lose depends on how much it spends during an election, as well as on the number of women running. Based on the 2015 slates and 2011 election spending (2015 refunds are not available until June), the Conservatives would stand to lose the most at $1.2 million, the Liberals about $682,000, and the NDP about $102,000.

Stewart says a number of countries have a similar law, including Ireland, which nearly doubled the number of female candidates it ran in this year's national election. Forty per cent more women were elected to Ireland's legislature, although that still means only 35 out of 158, or 22 per cent, of legislators there are women.

"There have been similar results in France, and this has been very successful in other countries," Stewart told CTV News.

Conservative MP Lisa Raitt says she’ll vote against Stewart’s bill. She says Parliament needs to be a better workplace before more women want to run for office.

“We have to be looked upon as MPs, as equal, not as a woman first, not as a man first. And until I see some change like that in the House it's going to be really difficult to want to encourage other women to come in here,” she said.

Raitt, the Conservative Party's finance critic, says men on the Hill need to be more cognizant of how they treat women differently, even if they think they’re being chivalrous. She pointed specifically to a moment last week when Prime Minister Justin Trudeau hugged interim Conservative leader Rona Ambrose when she teared up during a statement on the devastating wildfire in Fort McMurray.

“They shouldn't look across and see a female leader who is crying during a speech and want to comfort her. They should see a leader who is emotional about a topic that's important to that leader and let them have their moment and show Canadians how they feel,” Raitt said.

“It really bothered me that the prime minister decided to insert himself in that moment. He wouldn't have done it with (Conservative MP) Jason Kenney. He wouldn't have done it with a Stephen Harper. But he did it with a Rona Ambrose.”

Stewart says the bill would force the parties to decide whether they want to encourage more women to run, or give up part of their election refund. He says it wouldn't directly interfere with party nomination processes.

"We have to learn from other countries and we have to do what they do in order to push our parties, to nudge them forward to run more women candidates," he said.

"It is about justice. It's about making sure that our House of Commons reflects our population, and right now, it doesn't... If we keep going at this rate, it's going to take 60 years in order for us to have gender equity in this Parliament, and that's too long."

With files from CTV Parliamentary Bureau Chief Joyce Napier.