Justice Minister Peter MacKay says that the Conservative government's newly proposed legislation will aim to strip parole eligibility from a "narrow category" of murderers who have committed acts of "extreme violence."

MacKay announced Bill C-53, also known as the "Life Means Life Act," in Ottawa on Wednesday.

The bill promises to target Canada's most "heinous criminals," and says it will keep the country's streets and communities "safe."

Offenders who have been sentenced to life imprisonment are currently eligible for parole after 25 years.

on Wednesday that bill limits parole and forces to "spend the rest of their lives behind bars" based on "past proven behaviour" of "extreme violence"

In a released on Wednesday, the government said that only those convicted of the "most serious murders" and "high treason" would be considered.

The bill proposes that mandatory sentences of life without parole would be applied in the following circumstances involving first-degree murder:

  • Sexual assault
  • Kidnapping or forcible confinement
  • Terrorism
  • The killing of police officers or corrections officers
  • Conduct of a particularly brutal nature

MacKay also said that life without parole could be waived in certain "circumstances of mercy."

He cited a terminal diagnosis, or if an offender was nearing the end of their life as potential examples.

Ultimately, offenders could apply for "exceptional release" after serving 35 years. The final decision would be made by the minister of public safety, which MacKay says adds "direct accountability" that "doesn't exist with the parole board."

The government's statement says that this exception was added to the bill to address "constitutional concerns."

MacKay said that legislation will ensure that the rights of victims remain at the "heart of our criminal justice system." He told Power Play last week, that Bill-53 will protect the families of victims from being "re-traumatized" by ongoing parole hearings.

However, critics suggest that the bill is simply a political maneuver part of the Conservative's broader agenda to appear tough on crime.

NDP Leader Tom Mulcair said on Wednesday that the bill is unnecessary because judges already have the power to "declare someone a dangerous offender" and lock them up "as long as they have to protect society."

"Either Stephen Harper's an incompetent and this terrible problem has been left unchecked for the 10 years he has been in power, or he's playing another political game," he said on CTV's Power Play.

Liberal Leader Justin Trudeau said that Canada's justice system already "recognizes" that killers who are a risk to reoffend, such as Paul Bernardo and Robert Pickton, should not be granted parole.

"I think a lot of this is campaigning on fear, which (Harper) is extremely good at, but I think we can all agree that bad criminals should not be released and we have to make sure that we’re getting that balance right," Trudeau said.

Queen’s University law professor Allan Manson also said last week that parole boards are already effective at keeping the criminals targeted by the legislation in jail.

"The most heinous cases do not get out so this is not an issue of whether the Clifford Olsens will be released," Manson said, referring to the convicted serial killer murdered 11 people in the 1980s.

Canada’s Correctional Investigator Howard Sapers said last week that bill C-53 could also increase overcrowding in Canadian prisons.

Sapers said that by creating sentences without the possibility of parole there could be a "stacking effect" as new criminals join already overcrowded prison ranks.

"It will become nothing more than a holding pen because there’s no point in preparing these people for release, there’s no point in engaging them in vocational programming," Sapers told Power Play.

Sapers also said that there is research that shows lengthier sentences could contribute to criminality.

"When you take all hope away from somebody, you don’t give them any incentive to follow rules or be at all productive."

The legislation is the latest in a series of tough-on-crime bills pushed by the Conservative government.

In 2011, the Harper government struck down the "faint hope clause," which allowed criminals convicted of first- and second-degree murder to apply for an earlier parole eligibility date at the 15-year mark of their sentence.

The Conservatives have also added minimum sentences to a range of crimes, including drug and gun offences.