Members of Parliament debated  Tuesday a private member's bill that aims to part politicians from their pensions if they're convicted of a crime that carries a potential sentence of at least two years.

Conservative MP John Williamson admits he once called his legislation "the Mike Duffy bill" but adds, "Duffy is part of it, but he's not the only one carrying water on this." Duffy, one of three senators recently suspended from the Senate over inappropriate expense claims, has not been charged with any crime.

In the House of Commons, Williamson suggested a change to his own bill, upping the potential sentence provision to five years. This amendment, he said, would prevent a parliamentarian from losing his or her pension because of being convicted of blasphemous libel, or setting off a false fire alarm, two offences that carry possible two-year sentences.

In a phone interview, Williamson said the idea for his bill was spurred by the conviction of former Liberal Senator Raymond Lavigne, who is currently serving a prison sentence for fraud stemming from his expense claims while he was a member of the Senate. Lavigne is collecting both an MP's pension and a Senate's pension, despite his conviction.

Since then, suspended Conservative senators Duffy, Pamela Wallin and Patrick Brazeau and former Liberal Senator Mac Harb, have had to repay inappropriately claimed expense money, and are being investigated by the RCMP.

"I'm counting this bill is going to be popular with the tax-paying public, so I'm hoping it's going to pass," Williamson said.

He said he has the support of Treasury Board president Tony Clement. "Tony has been working with me and has been helpful," he said.

Williamson also pointed to an email sent by NDP Leader Tom Mulcair to a constituent who wanted to know the NDP's position on the bill.

NDP and Liberals onside

"Please know that the NDP will support this legislation because we believe deeply that Canada's legislators should abide by the law of land," Mulcair wrote.

But he added, "We feel that this is a half-hearted attempt by the Conservative government to restore its reputation badly damaged by the growing number of scandals under its watch."

In debate, the NDP's Peter Julian and Liberal MP Scott Simms both said they'd support the bill, but Julian wondered if the bill should allow for spouses or ex-spouses to access convicted politicians' pensions.

Williamson replied he believes "we should not treat ourselves terribly different than members of the public." He pointed out that if someone loses their employment insurance payments because of fraud, there is no obligation to give that money to dependants.

He added that by 2016, MPs' personal pension contributions will rise to $38,000 a year, and, over six to 10 years, that money could add up to $300,000 to $500,000, minus the government's contributions, an amount that could be available to spouses and dependants.

Politicians affected by the legislation would be refunded their own pension contributions, with interest, but would not get anything else.  

"If a senator or MP steals from taxpayers, they don't deserve taxpayers' funding, or buying them gold-plated pensions," Williamson said.

His bill applies only to federal politicians, although he points out he modelled the bill's language after legislation passed by the Nova Scotia government that has already resulted in one member of the provincial legislature being stripped of his pension after serving six months in prison for fraudulent expense claims.

Gregory Thomas of the Canadian Taxpayers Federation said his organization sees the bill as a deterrent.

"We've seen in the Lavigne case, he was charged with 50 odd counts of wrongdoing. He ends up with a six-month sentence. Did he go through some sort of calculation? 'Well I might get caught, if I did get caught I'd probably be able to beat it, ... and I really need the money and this is a risk I'm willing to take?' Pragmatically speaking, I don't think too many MPs or senators would be willing to bet their pension."

Extending the bill?

Williamson said some of his Conservative colleagues would like to see the bill extended to the entire public sector, but, "In a private member's bill I decided to bite off what I could chew"

Many MPs were dismayed when they learned serial killer Russell Williams would be able to collect his $60,000 annual pension he'd earned after spending two decades in the military. 

Even though the military burned the former air force colonel's uniform and destroyed his medals, it was powerless to stop his pension. Williams was sentenced to life in prison for the brutal sexual assaults and murders of two women while he was serving in the forces.

Sources have told CBC News that the government, angered by the colonel's case, has considered its own bill that would apply to the broader public service.

Williamson's bill, titled Revoking Pensions for Convicted Politicians, will be debated one more day about a month from now, before it's sent to a parliamentary committee for further study, and then back to the House of Commons for a final vote.