The new sentencing guidelines in England and Wales say blaming others should be considered an "aggravating factor" when deciding a sentence.
The change comes after many cases where one parent or carer sought to blame the other for what had happened.
The Ministry of Justice backs the plan, saying child cruelty is "abhorrent".
The proposed guidelines are to be applied in those cases where there are charges of cruelty to a child, allowing a child to die or suffer serious physical harm, or failing to protect from a young girl from female genital mutilation (FGM).
The Sentencing Council has launched a public consultation over the proposals.
To date, there have been no convictions under laws relating to FGM in England and Wales despite estimates suggesting it has affected tens of thousands of women and girls.
The Sentencing Council said the guidelines have been designed to allow a "better assessment of these complex offences" to help ensure "consistent and proportionate sentencing".
The wide range of offending coming before the courts could involve incompetent parenting to deliberate abuse.
The aggravating factor of blaming others was proposed because such cases frequently involve one parent, carer or guardian seeking to blame the other for what happened in order to avoid prosecution, said the council.
Mrs Justice Maura McGowan, a member of the Sentencing Council, said: "These offences are committed against particularly vulnerable victims - children - and so we want to ensure that sentencing properly reflects the harm they have suffered.
"Offences vary greatly - some offenders may be guilty of a one-off lapse of care which puts their child at risk of harm while others may have inflicted a campaign of deliberate cruelty.
"The proposed guidelines set out a clear approach to deal with such a range of offending and ensures that cases involving significant force, a weapon or multiple incidents of cruelty are always treated as being in the highest category of culpability."
An MoJ spokesman said: "Child cruelty is abhorrent and the impact on victims can be immeasurable. Those who harm children should feel the full force of the law."
Abusive or neglectful parents who blame their partner for their own child cruelty could face tougher sentences in new court proposals.