For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
I worked in a few schools and homes for the elderly. The guardian of the child, the carer has a duty of care, every one who works with children has a duty to safeguard the child. Neglect is a form of abuse, not providing what the child needs, depriving the child of basic daily routines, taking away the dignity of him/her and many other actions.
Neglect will severely impair the proper growth, the emotional development of the child , impact the health and character. Neglect can leave the child vulnerable to exploitation, bullying, wrong companions, more abuse.
It will not give a proper education and will result in a frustrated young adult.
I would contact the school first and ask them to whom it shall be reported.
Otherwise contact the local social services, a local children charity like Bernardo's or the NSPCC, you can find information on google.
Contact the local social services at your council, family doctor surgery, the social services, the local church if applicable, neglected children might have never attended one.
Children are a gift from God any form of abuse it's a rejection of such a gift, it's like making the child pass through the fire, it is causing a stumbling block.
Do you think the child will receive a Christian education in such an environment?
You must report it if you witness it, but do not confuse financial difficulties for neglect, in that case examine the financial situation of the parents first.