Ten families have instructed lawyers to sue University Hospitals Bristol NHS Trust over the way their children were treated between 2008 and 2012.
Seven children died as a result of negligent care, according to the families, whilst the children of the remaining three families suffered from serious treatment complications.
All the incidents relate to children with heart problems treated at the Bristol Royal Hospital for Children. The families claim that nursing staff shortages were to blame for many of the complications that arose, saying that they were often left to provide much of the nursing care themselves.
Families also explained that their pleas for attention were ignored when monitoring alarms were sounding and that in some cases nurses adjusted the alarms so that they were disturbed less often.
One of the tragic fatalities was that of Maisie Waters, who was just one week old when she died last August. An investigation into her care revealed that she was fed a day's worth of food in just one hour by nursing staff that her distraught mother claim were 'laughing and joking' whilst preparing the food instead of concentrating on the task in hand.
Two of the families raised a complaint and the Care Quality Commission did visit the hospital, finding a dangerously low level of nursing staff that they believed was insufficient to keep people safe.
"All we want is the truth. After the nightmare we lived through with Sean, we deserve nothing less than the truth. That is vitally important for other families as well," said Stephen Turner, the father of Sean Turner who died from a brain haemorrhage.
The Trust maintains that it remains one of the leading centres for paediatric heart surgery in the UK.
"Despite the risks and the complex needs of the children we care for, we have results among the best in England," said Robert Woolley, the Trust's Chief Executive.