The mother of a two-month-old boy who was left severely disabled after being shaken and thrown in the air has called for his attacker’s jail sentence to be extended.

Jay Bell, 23, was jailed for four years last week after admitting culpable and reckless conduct towards the baby to his severe injury, permanent impairment and to the danger of his life.

He also admitted wilfully neglecting the baby and failing to seek medical attention.

The boy suffered brain damage after the incident in July 2013 and his mother, who cannot be named for legal reasons, said the four-year jail term was too lenient.

She has written to the Crown Office and Procurator Fiscal Service (COPFS) to call on prosecutors to appeal the sentence, and more than 500 people have signed an online petition supporting her campaign.

His mother told STV News on Wednesday: "The sentence is pitiful. I feel like it’s not enough for the crime that he committed."

Bell, of Mayfield, Midlothian, threw the child repeatedly in the air but the baby struck his head on a wall, hit a Moses basket and fell to the floor. He then shook the child a number of times.

The baby developed cerebral palsy following the incident and is now registered blind.

His mother said her son, now two, was a "different child", adding: "He can’t do anything, he can’t even eat solid foods, he can’t sit up by himself. He can’t talk.

"[At first] the chances he had of survival were very slim. He is seen by a medical professional every single week. It’s an ongoing thing that he’ll never recover from."

A spokesman for the Crown Office and Procurator Fiscal service said: "The Crown is considering whether there are grounds for lodging an appeal against this sentence. In all court cases, prosecutors consider whether a sentence is 'unduly lenient'."

To decide whether or not to appeal, COPFS has to prove the sentence is outwith the range of sentences which the judge could "reasonably have imposed".