It is obvious why billionaires dine with Tories at the kind of balls that even the sillier fairy princesses would avoid: it's the access, reader. The Tories were keen to hide the specific details of their "secret" fundraising ball, but the truth finally came out this week. Guests ate guinea fowl and salmon; someone stupid enough to pay £90,000 for a bust of David Cameron's head (like his own, but eternal) was found and applauded, and Peter Stringfellow, the jangly people's pimp, was there. Need we know more?

Less secret was the party thrown in the great court at the Foreign Office this week to honour the "entertainment industry", although it was hardly less embarrassing. A gaggle of decrepit celebrities, including the fearsome light entertainment triumvirate of Cilla Black, Ronnie Corbett and Bruce Forsyth, appeared to hear the prime minister tell them, "You make your country so proud." (Why the entertainment industry? Why not the fishing industry? Or cows?)

I could suggest that Cameron was lying – by his small lies shall you know him – but perhaps he meant it. Perhaps Cameron's political antennae are so cracked he really believes he can reanimate Cool Britannia and get some friendly headlines with this lot? (Maybe they could call it Gruel Britannia this time around?) He had no such luck. The media speculated that he had invited "hotter" and "more interesting" (that is, "better") celebrities – such as Helen Mirren and Benedict Cumberbatch – but they freaked out, and firebombed their cars and ate their shoes rather than attend a coalition government event, and so forth. Cameron was left with his personal friend the actress Helena Bonham Carter, who sometimes pops up with testimony relating to the prime minister's "real compassion".

None of this will do. Celebrity involvement in politics is a wretched thing. It should be consigned to dust, especially post-Jimmy Savile – who spent many holidays at Chequers with Margaret Thatcher, during which he used to write "In case of national emergency, phone Jimmy Savile" on every notepad in the house, should you need a nightmarish image to chew on. Have our leaders not learned to hide from these terrible narcissists? Celebrity is trivial, and when it moves close to power, it trivialises that too. The gongs for light entertainment heroes, meanwhile, insult everybody: a gong for a laugh. Is leering on Strictly Come Dancing and clutching female contestants' arms really a public service meriting a knighthood?

Often, when embracing politics, the celebrity looks foolish and starstruck, removed from his calling – Noel Gallagher, for instance, when he shook hands with Blair and smiled and Blair smiled back, in a perfect pottage of smug smiling. And Jim Davidson always. (Now, I hear, Davidson is an embarrassment to the Tory party that used to fete him. What took them so long?) How did the guys of Cool Britannia (1997 incarnation) feel when Blair finally basted that trend in blood? From the perspective of history, Cool Britannia was only a subeditor's slick pun. It played well in magazines. It meant nothing.

Sometimes the celebrity becomes genuinely politicised, which only compounds the danger. I speak, of course, of Russell Brand. He believes, among other things, that abolishing democracy will make Britain a fairer place and promises to enlighten us further on his revolutionary plans in due course. His narcissism is not strange: he is a comic by trade, and is used to drooling rooms of strangers. Politicians should know better than to touch it; or perhaps they recognise it? What did Thatcher see in Savile, and vice versa? We will never know.

Now Cameron, too, has his national treasures – Black, Forsyth and Corbett – for his photograph album. Again, there is danger here for people who like their politics sincere; I am not entirely certain that every single "national treasure" I have interviewed was not a sex offender or, at the very least, a compulsive litterer or a tax dodger.

The national treasure brand is broken. Don't come for Tony Hart – or Mr Blobby or Dusty Bin – is the cry in the night. But the death of naivety and TV niceness is not a terrible thing. Why should we exalt such creatures, who speak only to children, and in children's words? Clear them all away – from politics, from everywhere. We must do better.

Twitter: @TanyaGold1