Members of Parliament debated the Conservatives' controversial omnibus crime bill Tuesday in what might be the last chance for opposition members to push for changes before bill C-10 becomes law.

The Safe Streets and Communities Act is at the report stage after it was dealt with clause by clause last week by the justice and human rights committee.

The omnibus bill, in its third and final reading, combines nine previous bills that died before the federal election, into one.

NDP MP Isabelle Morin called on the government to focus on preventing crime, rather than increasing sentences and therefore filling up jails with more convicts, rather than reducing crime rates.

"Increasing mandatory minimums will not prevent crime, it will not make our communities safer," Morin said.

"There have been many specialists who have come to provide their opinions based on scientific fact and the government continues to say based on our experience we think we should do this."

She also read a letter she had received from a constituent in her Quebec riding of Notre-Dame-de-Grace—Lachine, who said they had been convicted of a crime more than a decade ago and had moved on with their life and become a contributing member of society.

However, the constituent complained that tough new rules in Bill C-10 would make it difficult for those convicted of a crime to rehabilitate and move on from their past.

Morin was just one of many opposition MPs expressing serious concerns with the bill's punitive focus.

Other opposing witnesses expressed concern about effect the legislation would have on the courts, prison system and young offenders.

Liberal MP John McCallum said the Conservatives were returning to a "Middle Ages" approach that focused on "vengeance" against those who break the law, rather than rehabilitation. At a time when criminal offences are declining, McCallum said, Bill C-10 will actually have the opposite effect.

"This plan to dump thousands of new offenders into the system will simply break it. Low-level offenders will enter the system after convictions for petty crimes and they will leave having made new criminal connections and having learned the skills of the trade. That should never be the outcome of our justice system," McCallum said.

Conservative MP Kyle Seeback defended against the criticisms, suggesting the Conservatives were the only MPs putting victims' rights first.

"The people who are on side and support this bill and say it's necessary are people like chiefs of police, victims rights groups and victims themselves," Seeback said.

The bill, which is in its third and final reading, was first tabled by Justice Minister Rob Nicholson earlier this fall, with the goal of having it signed into law by Christmas.

The bill must also pass the Conservative-dominated Senate, but will likely do so easily.

Liberal justice critic Irwin Cotler, NDP justice critic Jack Harris and Green Party Leader Elizabeth May have proposed 88 amendments to the bill -- most seeking to have clauses deleted from the bill.

However, they are limited to only proposing amendments to issues that have not yet been debated in committee. That meant Speaker Andrew Scheer deemed a number of those proposals to be ineligible.

The remaining amendments were divided into five different groups to be debated Tuesday.