The case of Roger McClay highlights a growing discrepancy between sentences for blue- and white-collar criminals, Opposition parties say.

The 65-year-old former Government minister was this week sentenced to 300 hours of community work after admitting defrauding two charities and the Parliamentary Service - the administration division of Parliament - of more than $24,000.

There was outrage earlier when Blue Chip founder Mark Bryers avoided a jail term after pleading guilty to 34 charges laid by the Ministry of Economic Development in relation to the running of companies in the Blue Chip group.

Nineteen companies associated with Blue Chip were placed in liquidation in 2008, affecting about 2000 property investors.

Labour MPs Charles Chauvel and Lianne Dalziel agreed with comments by people such as Kim Workman of Rethinking Crime and Punishment that people abusing positions of privilege and committing financial crimes got softer treatment than burglars.

"I have met many victims of these financial crimes who have lost their life savings through fraud," Ms Dalziel said.

"They are affronted that the sentence is invariably lighter for this kind of criminal as opposed to the one who breaks into their property and steals items that don't even amount to a fraction of that value."

Mr Chauvel said inconsistent sentencing was a problem the Law Commission had highlighted.

A Sentencing Council would help reach a consistent approach, he said.

"In this country there is no justice of the poor and it's been like that for decades. Maori communities will tell you that as well as poor communities. The discrepancy between those who steal from the local shops or those who steal millions of dollars from investors highlights the fact that there is no justice if you're poor and don't have privilege."

Greens co-leader Metiria Turei said there were two rules: "In the end if you're a privileged person you have your privileges taken from you as punishment but if you have no privileges you have your freedom taken from you as punishment. That is not fair, it's not just, but it's been the way of this legal system for many decades.

"Often sentences are lower for those who have reputations because their reputations are damaged. Well if you're a thief you're a thief and you should be punished like a thief, whether you're a rich thief or a poor thief. The consequences of your crime need to be taken into account, not your status as a human being."

Justice Minister Simon Power said he left sentencing decisions to the judiciary.