The federal government is committed to introducing mandatory minimum sentences for those convicted of certain crimes, Justice Minister Rob Nicholson says.

The Canadian Bar Association passed a resolution on the weekend at its annual conference in Halifax calling on the government to give judges more discretion in cases where there could be an injustice by use of a mandatory minimum sentence.

But Nicholson told the association Monday that minimum sentences are "reasonable and appropriate" for some offences.

His government wants mandatory minimum sentences for sex offences against children and for many drug crimes.

Proposed legislation contains a number of new provisions including new minimum and maximum guidelines for organized drug crime and sexual predators.

The Conservatives were unable to achieve those changes as a minority government, but are committed to passing them now.

Leeway needed for mentally ill, lawyers say

The Canadian Bar Association wants a so-called "safety valve" that would allow judges to have leeway in sentencing those who are mentally ill, those who suffer from a permanent brain injury or those suffering from fetal alcohol syndrome.

"If there is no safety valve in the system, then there is no option for judges, that sometimes they’ll have to incarcerate people that would be better treated in the community or treated in another way, and that’s very unfortunate," said Dan MacRury, who worked as a defence lawyer in Nova Scotia before becoming the chief Crown prosecutor for Cape Breton.

"Too many people who suffer mental illness in this country are being treated by the criminal justice system as opposed to the mental health system. It's a concern that we have that certainly has to be addressed."

MacRury said the association will continue to push the government on the issue.

Other countries with mandatory minimum sentences have adopted the "safety valve" measure, including the United States, United Kingdom, South Africa and Australia, the bar association says

Nicholson said judges will have to work within the upper and lower sentencing limits set by Parliament.

"We set the maximum, that’s our obligation to do. And in some cases we set a minimum, and within that framework the judiciary can decide what’s appropriate."

Winnipeg lawyer Brad Regehr, who speaks for the bar association on aboriginal legal issues, worries that mandatory minimum sentences will reverse years of effort to lower rates of First Nation incarceration.

During an interview on Power & Politics with Evan Solomon, Canada’s Safety Minister Vic Toews accused the bar association of consistently opposing the government’s initiatives to get criminals off the streets.

"Our government has made it very clear that public safety comes first and that those who are dangerous offenders will find themselves in prison, that’s the promise that we make," Toews said.

The federal government has promised to bring the new mandatory minimums into law before the new Parliament has sat for 100 days.

With files from Jack Julian and The Canadian Press