A baby is fighting for his life after suffering horrific injuries in a smash involving an ambulance and a police car.

The parents of the four-day-old boy kept a vigil by his bedside at the Paediatric Intensive Care Unit at Guy's Hospital after he was transferred from another unit.

The baby, who is suffering from a heart condition, sustained a fractured skull and internal bleeding when the ambulance overturned.

A Police Complaints Authority inquiry has been launched into the crash in Kennington, south London, which happened as the ambulance was carrying the baby from Eastbourne District General Hospital to King's College Hospital, London.

The police were responding to a vehicle pursuit call in south London at 3.35am yesterday.

The baby's parents, from the Eastbourne area, were following close behind.

The ambulance driver remains in a critical condition at King's College Hospital, while two staff accompanying the baby have been discharged.

The Metropolitan Police voluntarily referred the incident to the PCA. Authority member Marcus Williams will supervise the inquiry.

Neither of the police officers, the male driver and female passenger, required hospital treatment.

Hospital trust chief executive Dr Jonathan Michael said: "This is a very tragic incident.

"Our immediate priority is to provide the best possible care to the baby involved in the accident and support the parents.

"We're all extremely concerned about the serious condition of the ambulance driver who is being treated at King's College Hospital."

"We've launched an immediate internal investigation to find out exactly what happened and will of course co-operate with investigations by the police."