EXCLUSIVE: MURDERERS, drug traffickers, child molesters and killer drivers can expect much harsher penalties under laws to be introduced in State Parliament this week.

Attorney-General Robert Clark’s reforms will throw out current sentencing guidelines for a range of offences, in favour of harsher “baseline” penalties set in legislation.

Judges will still be able to impose shorter or longer sentences than the baseline, according to the severity of the offending.

But the new law will also fix mandatory minimum non-parole terms, to be set as a proportion of the head sentence.

The reform, to be introduced on Thursday, has been a subject of fierce debate behind the scenes between the Government and senior judges.

Earlier this year Chief Justice Marilyn Warren and County Court Chief Judge Michael Rozenes wrote to Mr Clark, warning the proposed law was unworkable.

media_camera New baseline sentences will be established for some of the most violent crimes.

The Government has since rewritten the law to take note of some of their concerns.

But senior legal figures are still concerned that the new law will be impractical.

The new baseline sentence for murder will be 25 years, six years longer than the current average sentence of 19 years.

Trafficking in a large commercial quantity of a drug of dependence willattract a baseline term of 14 years, instead of the current average of seven.

The new baseline sentence for sexual penetration of a child under 12, and persistent sexual abuse of child under 16, will be 10 years; the current averages are 3½ and six years respectively.

The baseline sentence for culpable driving causing death will be nine years, up from the present 5½.

Under the new law, criminals sentenced to less than 20 years will have to serve at least 60 per cent of the sentence.

Those sentenced to 20 years or more will be required to serve a non-parole period of at least 70 per cent of the term.

Those sentenced to life imprisonment will have to serve a minimum non-parole period of at least 30 years.

Mr Clark said at the moment, the average sentence for some of these crimes was “appallingly inadequate”.

The new law is the first stage in the Government’s planned rollout of baseline sentences, in which Parliament will specify the average or median sentences that the courts will be required to apply.

“Under this reform, the law will require that cases of the sort that previously received the old median sentence will, in future, receive the baseline sentence,” Mr Clark said.

james.campbell@news.com.au