Former attorney-general Philip Ruddock says children should not be denied the opportunity to have an equal relationship with both parents in custody disputes amid an ongoing debate over Labor’s push to amend the Family Law Act.

The former Liberal minister, who presided over the portfolio when the Howard government undertook significant reforms including the introduction of the presumption of equal shared parental responsibility, said children had an entitlement to know both parents in circumstances where they are not facing harm.

“You don’t have children without a mother and a father, and children have an entitlement to be safe, but if they are safe and secure one would not want to see a situation where a loving parent was denied the opportunity to see their children,” Mr Ruddock said.

“When children are safe and not the subject of any intimation or violence it is desirable that they have the opportunity to know both of their parents.”

Labor is seeking to abolish the presumption of shared parenting in court disputes. This directs a court to apply the presumption that it is in the best interests of the child for the parents to have equal shared responsibilities.

It comes despite a 2019 Australian Law Reform Commission review which did not recommend abolishing the provision, but proposed the clause relating to the presumption of shared parenting be reworded to allow “joint decision-making about major long-term issues”.

The move has caused anger among some legal professionals who have expressed concern its removal may diminish the ability for both parents to have equal responsibility for their child.

The most expansive evaluation of the Howard government’s 2006 reforms, undertaken by the ­Australian Institute of Family Studies in 2009, found the amendment of shared parenting led to an increase in the number of children who had meaningful relationships with both parents.

It also noted that the reforms helped dispel community perceptions that mothers should have the majority of time with their children after separation, including a reduction in emphasis of the 80-20 rule which underpinned an ­assumption that mothers would be responsible for the bulk of the childcaring duties following a relationship breakdown.

AIFS lead author Rae Kaspiew said the 2006 reforms impacted the outcomes of family disputes because they changed the way parents entered negotiations, with many believing they were entitled to 50-50 shared care.

However, she said shared ­responsibility may not be in the best interest of the child, especially when there is evidence of domestic violence or abuse.

“Over time, research that the AIFS has conducted has suggested that the presumption creates expectations which may not be compatible with arrangements that are in a child’s best interests and that it can also result in parents agreeing to shared parenting agreements in circumstances where that’s not in the best interests of children,” Dr Kaspiew said.

The 2009 review also found many legal professionals believed the 2006 reforms had favoured ­fathers over mothers, and saw an increase in bargaining dynamics such that mothers were “on the back foot”.

The review found the overall incidence of shared care had increased, with the proportion varying considerably according to the age of the child.

However, shared care arrangements were only experienced by a minority of children, with most spending most or all nights with their mother.