But the Australian Law Reform Commission,which delivered a major report on the family law system last year,found the provision was being misinterpreted to mean both parents should see the child for the same amount of time.
"The widespread nature of that misunderstanding has a number of effects,including leading unrepresented parties to believe they have no choice but to agree to equal time and to enter into informal agreements based on a misapprehension of the law,"the ALRC said in its final report.
Mr Ronalds said:"The presumption is harming children by leading to them being placed in contact with parents where such contact is unsafe."
The presumption does not arise in cases of abuse or violence,but Mr Ronalds said the family law system was also bad at evaluating those claims.
"Our concern is that the system is still failing to listen to the very people it is entrusted to represent and protect – children,"Mr Ronalds said.
The family law inquiry,one of several recent examinations of the contentious area of law that governs topics including what happens to children when a couple gets divorced,wasestablished by the government in September after pressure from One Nation leader Pauline Hanson.