When a court makes an order on the care and control of a child whose parents are splitting up, it does not presume that shared care and control are always in the child's welfare.

Neither is there any legal principle against such an arrangement.

Rather, the focus is always on the child's welfare, and not the interests or wishes of either parent.

The High Court said this in a judgment yesterday in the case concerning the divorced parents of a girl who have been tussling over her care arrangements since 2013.

"By focusing on the child's welfare, the courts remain vigilant that custody, care and control, and access are not used by a parent as 'instruments of control' over the child and the other parent," said Justice Debbie Ong.

The case, which raises the question of how the notion of joint parental responsibility should be applied to determine orders for care and control, and access, centres on a girl who will turn six next month.

Her parents are British citizens who have lived in Singapore since September 2011.

Her mother filed for divorce in Britain in July 2014, and a decree absolute ending the 11-year marriage was granted in May 2016.

In Singapore, the legal fight over the girl's care culminated in a High Court decision in May 2015.

The couple were given joint custody of the girl, meaning they have to consult each other and jointly make major decisions for her. This includes decisions on healthcare and education issues.

Care and control of the girl were granted to the mother. This means she is the primary caregiver responsible for making day-to-day decisions, such as what the child is to eat.

In August 2016, the father applied to vary the orders made by the High Court. Among other things, he sought shared care and control of the girl as well as access to the girl during school holidays, public holidays and Father's Day.

A district judge allowed parts of his application in relation to the terms of access, but declined to grant shared care and control.

The judge said such an arrangement - which means the girl would effectively split her time between two homes - would not work because of the parties' acrimonious relationship and their different parenting styles. The father appealed against the decision.

Justice Ong varied a few aspects of the district judge's orders on access but dismissed the father's request for shared care and control.

In her judgment, Justice Ong said that in appropriate cases, the court may grant both parents shared care and control if this was feasible and best served the child's welfare.

But in the current case, she said it was not necessary as both parents have joint custody. She added that the girl will start primary school later in the year, and shared care and control may not be practical.

Justice Ong concluded that the district judge's order for sole care and control to the mother, with liberal access to the father, was not wrong and in fact supported the girl's welfare.