My son wants to take legal action, help!?

there is no precident particularly in the UK for a child to persue the father for neglect as long as there is a parent present, which was you, then the court will see no real problem, as many children are brought up in single parent families. only if the child was in his care, and was neglected in terms of being left at home and there was a serious accident, then there would be grounds for prosecution, however simply being absent is no real grounds.