A man jailed for killing his victim with one punch is to have his sentence referred to the Court of Appeal.
Andrew Young died in hospital after the assault outside a supermarket in Bournemouth, Dorset, last year.
Lewis Gill 20, of Ridge Road, Sutton, was given a four-and-a-half-year jail term last month at Salisbury Crown Court after admitting manslaughter.
Mr Young's mother Pamela had described the sentence as "a joke".
The 40-year-old, who had Asperger's Syndrome, suffered a head injury during the assault, that took place after he had challenged a cyclist who was riding his bike on the pavement.
He died later in hospital.
Gill was arrested in Croydon.
Lewis Gill's punch that killed Andrew Young
A spokeswoman for the Attorney General's office said: "Having carefully reviewed this case, the Attorney General, Dominic Grieve QC MP, has decided to refer the sentence of Lewis Gill to the Court of Appeal for review.
"The case will in due course be heard by three Court of Appeal judges who will decide whether they should increase the sentence."
The case is expected to be listed at the Court of Appeal within the next five to seven weeks.