HOW do you know when you’re time’s up?

This week poor millionaire Mr Smedley, of canned-food fame, decided before BBC Two cameras that his motor neurone disease should be ended during a trip to Swiss clinic Dignitas.

However, Professor Stephen Hawking, once told he wouldn’t survive his twenties with the same disease, is still around at the ripe old age of 69.

When we play God and decide ‘thou shalt kill’, pitfalls are deep and numerous.

The pressures on those seriously ill to go rather than be a bother would be immense with legalised euthanasia, especially from those who would profit from quick deaths — unscrupulous relatives and a hard-pressed medical profession short of beds and money.

Add to this the characteristic reluctance of the elderly to be a nuisance and how can we ever be sure that assisted suicide would be a truly voluntary and deliberate act?

This would be doubly true if euthanasia blossomed into a right as indeed has abortion. The old would become as vulnerable and inconvenient as the unborn. Not that the BBC appear too bothered.

This is the fifth time they have produced a glorified promotion for assisted suicide since 2008, causing four senior peers to accuse them this week of running an ‘orchestrated campaign’ to change the law on DIY death.

And this is despite high protest numbers. This time 900 viewers protested while a mere 80 supported the BBC programme fronted by Alzheimer sufferer, novelist Sir Terry Pratchett. Once remove the sacredness from human life and death, and we fall into an abyss so deep that we might never get out.