Why is Arthur Picton standing naked outside his house and why is he facing Christmas alone?

Maureen has her hands full at home and can't take care of her father William, who may be suffering from Alzheimer's. Her brothers - Alun, an alcoholic trumpet player, and John, an insensitive businessman - don't really want to help. William, a lifelong socialist, feels angry and resentful towards the British government which has abandoned him in his old age. Having been persuaded by his children to buy a council house in the booming 80s, he discovers that this selfsame government, which made such a virtue of home ownership some ten years earlier, now expects him to sell the property in order to pay for his care. Isolated in old age, Williams secretly decides to put into action a plan to get back at the system.

Why is Arthur Picton standing naked outside his house? Why is he facing Christmas alone? Classic Christmas comedy with Arthur Picton and his football team.