FIANNA Fail and the Progressive Democrats have condemned the commission's proposal to abolish mandatory life sentences for murder.
The Fianna Fail justice spokesman, Mr John O'Donoghue, said it was "imperative that society should send out the clear and unambiguous message that it abhors the intentional taking of human life".
Mr O'Donoghue said his party also opposed the proposal which could include the abolition of the 40 year minimum sentence for murder of a garda.
"We have an unarmed police force and the importance of the protection of its members was underlined up to recently by the fact that the penalty for the murder of a member of the Garda Siochana was death. Its replacement by a 40 year term of imprisonment was seen as an appropriate response following upon the abolition of the death penalty. The retention of this is particularly important in the light of recent events."
Judges should be free to impose terms of imprisonment within parameters set out by the Oireachtas, said Mr O'Donoghue. However, the Oireachtas should retain the power to provide for minimum or mandatory sentences so that "society's abhorrence of certain offences can he reflected with a guarantee of implementation".
He said in 1977 the Oireachtas provided for a minimum sentence of 14 years for drug pushing and increased this to life in 1984. However, in 1993 there were over 70 such cases before the courts and the average sentence was two years.
The PD's justice spokeswoman, Ms Liz O'Donnell, said society had to send a very strong message to criminals that their crimes would not be tolerated.
"There has never been a more important time for sure footedness and for clear, unequivocal signals to be sent to criminals who are contemplating, or committing, crimes. The deterrent effect cannot be underestimated."
Judges should have the power to impose fines instead of, or in addition to, a custodial sentence, she said. "On white collar crime, there is a definite ambivalence at the moment, both in the prosecution and in sentencing policy. This is wrong, it smacks of selective justice based on class."