Gangland criminals and terrorists convicted of murder should serve at least 15 to 20 years in jail, Minister for Justice Michael McDowell has said.
He was speaking today at the publication of the Parole Board's annual report, which revealed that 200 people are serving sentences for murder in Irish jails.
One in five of those will serve over 20 years, and most will spend at least 13 to 15 years behind bars, according to the minister.
"Sometimes the timeframe for the first review of a life-sentenced prisoner by the parole board after a seven-year period of detention has led - wrongly - to an assumption that life sentence prisoners are then released," he said.
Mr McDowell added that convicted murders should not expect to be paroled for at least 12 to 14 years, even in the absence of aggravating factors and where guilt has been admitted, remorse shown, and good behaviour in prison and a capacity for rehabilitation proven.
But he stopped short of advocating sentences without the possibility of parole.
"Life without parole is a proposition that is not known in Europe except in the most extreme of cases. Europe has a different jurisprudence to North America in this respect, and Ireland is part of mainstream Europe in those matters."
Labour's justice spokesman criticised the Minister's comments saying he was suggesting the judiciary and parole board are to blame for early releases.
"He is the only person who can determine the length of a life sentence, so if life they are too short, he's the one who is responsible," Mr Costello said.
The Parole Board report said the body dealt with almost twice as many cases in 2005 as in the previous year.
Some 66 inmates participated in reviews, including 16 murderers and nine sex offenders. In all, 46 recommendations were made to the minister, and one prisoner was released by order of the courts during review.
Earlier this month, Taoiseach Bertie Ahern said a life sentence "should mean life".