The Parliamentary and Health Services Ombudsman was set up by Parliament to provide an independent complaint handling service for complaints that have not been resolved by the NHS in England and UK government departments. They combine the two statutory roles of Parliamentary Commissioner for Administration (the Parliamentary Ombudsman) and Health Service Commissioner for England (Health Service Ombudsman).
They share findings from their casework to help Parliament scrutinise public service providers. They also share findings more widely to help drive improvements in public services and complaint handling.
Website: https://www.ombudsman.org.uk/