It's up to parliamentarians to set sentencing guidelines, Justice Minister Rob Nicholson said Tuesday after the Canadian Bar Association asked for leeway in mandatory minimum sentence provisions.

"It's our job as parliamentarians to set maximum guidelines and minimum guidelines where we think appropriate," Nicholson told host Evan Solomon on CBC's Power & Politics. "That's our job as legislators."

"These are the judgment calls that we make as parliamentarians and I think that they're appropriate. We're going after those individuals who commit crimes with guns, people who sexually exploit children."

The Conservatives have promised tougher sentences for certain crimes and are planning to bundle them into an omnibus crime bill. Prime Minister Stephen Harper has promised to pass the bill in the first 100 days following the return of the House of Commons June 2.

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, 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.

The association represents 37,000 lawyers in Canada.