Warning: Some readers may find this article distressingThe prison sentences handed to the killers of six-year-old Arthur Labinjo-Hughes have been referred to the Court of Appeal for being too lenient.
Earlier this month Arthur's father, Thomas Hughes, was sentenced to at least 21 years for the manslaughter of his son, after the child suffered an "unsurvivable brain injury" on June 16, 2020.
The schoolboy, whose body was also covered in 130 bruises, died in hospital the next day.
Hughes' partner, Emma Tustin, carried out the murder while in the sole care of Arthur at her home in Cranmore Road, Solihull, violently shaking him and repeatedly banging his head - likely against the hallway wall, floor or door, the court heard.
Tustin was sentenced to at least 29 years.
"Manipulative" and "calculating" Tustin was unanimously convicted after an eight-week trial trial, with the boy’s "pitiless" father Hughes, 29, found guilty of his manslaughter, after encouraging the killing.
Hughes’ "infatuation" for Tustin had "obliterated" any love for his son, sentencing judge Mr Justice Mark Wall QC told the court.
A petition launched in the aftermath of the sentencing, calling for whole life sentences for child killers, has surpassed half a million signatures.
Referring the case to the Court of Appeal, Attorney General Suella Braverman said: "This is an extremely upsetting and disturbing case, involving a clearly vulnerable young child.
"Emma Tustin and Thomas Hughes grossly abused their position of trust and subjected an innocent child, who they should have been protecting to continued emotional and physical abuse.
"I understand how distressing the public have found this case, but it is my job to decide if a sentence appears to be unduly lenient based on the facts of the case.
"I have carefully considered the details of this case, and I have decided to refer the sentences to the Court of Appeal as I believe them to be too low."
A date for the hearing at the Court of Appeal is yet to be set.