As Prince Charles turns 70, he faces becoming a new king while in old age. What could be worse?

Starting a job at his age with no prospect of it ever ending is pretty grim. What Charles needs to do is some kind of job share with William: split the job 50-50

So Prince Charles turns 70 this week. I hope he gets everything he wants (whisky and socks probably), plus a good lie in.

There has been a great deal of speculation over the last week, as the heir to the throne approaches his big birthday, about what kind of king he might be. Not that the queen is ever going to die of course, but we have to cover all eventualities.

According to the press, he has promised to be “Charles The Non-Meddler”, which is a shame because he’s a good meddler, and apart from his views on architecture, which are prissy and dire (he belongs to the school of fake Georgian), his head and his heart tend to be for the greater good of everyone. Charles has been battling climate change and pollution since the Seventies, and has not been shy of putting his money where his mouth is. He has even converted the royal train to run on used cooking oil, and his beloved Aston Martin to take a combo of surplus white wine and whey instead of petrol.

He was big on bees before many of us twigged how vitally important they are to the ecosystem, and as a fellow talker to flowers I am with him every step of the way when it comes to the power of horticulture. Then there’s his work with young people. The Prince’s Trust has been tireless in finding opportunities for disadvantaged young people since 1976, and all this from a man who could have spent his entire adult life lolling about on the sofa eating swan sandwiches.

I have no doubt that Charles would make a most excellent king. He’s spent enough time watching his mum, he’s got the right clothes, he knows which fork to use and he stands nicely. Oh and he kisses his sons. I love seeing fathers kiss their sons – it sends out all the right messages. Let’s face it, after a few duff moves Charles has turned out to be a pretty good egg – and as kings go, good egg-manship is pretty important.

But my issue is that it’s a hell of a job to take on at 70, and if I were Camilla I’d be horrified at the prospect because as Queen consort (a title which smacks of mistress and adulterer) she’s going to have to flog around the globe after him.

Just at an age when most old country birds are putting their feet up by the Aga and going out in a gilet and wellies to feed the chickens, or nipping round to Valerie’s for book club on Tuesday, poor Camilla faces potentially the next 20 years of constantly having to gussy up and wear those ghastly nude patent court shoes with a sensible heel.

Although now that Emma Thompson has gloriously broken the “trainers at the palace rule”, I see no reason why she shouldn’t be allowed to kit herself out in a snazzy pair of FitFlop trainers when she’s on duty. There’s a pastel pink pair that will go with anything.

Odd isn’t it that there’s no retirement age for a king or queen? Our monarchs are just meant to get on with it until they shuffle off this mortal coil, and considering none of them smoke these days that can be pretty old, and yet they’re not allowed to forget their reading glasses, the name of the prime minister or start telling the same story twice at the opening of parliament.

I’m not against people working into their 70s. Personally, I’m all for it. My partner is two months older than Prince Charles (but still has a mane of glossy white hair) and at 70 he is still working full time as a freelance designer, but at least he gets to come home most days for lunch, never has to wear a tie to work and we spend at least five nights a week in front of the telly eating our tea off a magazine (we don’t have trays).

Listen, I’m well aware that the old man is knocking on a bit. I don’t like Geoff working at the weekend never mind suddenly becoming the Head of State, Army and Church of England. When would he have time to watch Salvage Hunters: Classic Cars on Quest?

Also, his borderline diabetes would doubtless tip over the edge as I know he’d be rubbish at refusing a pudding at all those palace banquets. In fact, I guarantee he’d have gout within a fortnight.

What Charles needs to do is some kind of job share with William: split the job fifty-fifty. They could even have an electric works van with Windsor and Son written on the side.

No one is writing a 70-year-old off, but to be starting a job at this age with no prospect of it ever ending is pretty grim, and even though the last thing I want is Geoff retiring, getting under my feet and using up all my toilet paper, I’m eternally grateful he is never going to be a king.