Parents who have broken up must not depict one another as “ogres” to their children, Britain’s leading family law judge has said.

Speaking to Families Need Fathers, Sir Nicholas Wall, the President of the Family Division of the High Court, said separated couples often used their children as “both the battlefield and the ammunition” in their rows.

He said he wanted the family law system to be less adversarial but this was difficult to achieve because separating couples “rarely behave reasonably”.

Sir Nicholas said parents should play equal roles in the lives of their children.

He stated: “In the same way as it takes two human beings to create a child, and since most children learn their attitudes about the world in general, and the opposite sex in particular from their parents, the best upbringing for most children is in a household where there are two loving parents.”

He continued: “The separated parent’s role in the lives of his or her children retains the same degree of importance as when the parents are living together, even if the opportunities to manifest the qualities which an absent parent can bring to his children is limited.”

He said separation was a “serious failure of parenting”, and that post-separation, “there is nothing worse for children, than for their parents to denigrate each other.

“If a child’s mother makes it clear to the child that his or her father is worthless – and vice versa – the child’s sense of self-worth can be irredeemably damaged. Parents simply do not realise the damage they do to their children by the battles they wage over them.”

He added: “People think that post-separation parenting is easy – in fact, it is exceedingly difficult, and as a rule of thumb my experience is that the more intelligent the parent, the more intractable the dispute.”