Here's the latest entry in the diary of Rupert St John-Fontaine, adviser at the Department of Social Affairs...

MONDAY

IT’S the start of Platinum Jubilee Week and there’s a sense of genuine joy about Whitehall as we gather to mark the Queen’s 70th year on the throne. I’m still paranoid, though, about being revealed as a nationalist double-agent, and have taken to using the services of my old Ukrainian chum, Colonel Olaf, who has a private security firm as part of his extensive business portfolio.

The colonel spent 10 years as a Spetsnaz operative and has since used that expertise in the private sector (as well as assorted incriminating photographs of high-profile westerners) in his other interests which include construction, waste disposal and guard dog-breeding.

However, everything this week is geared for the platty jubes, as Boris now refers to it. The boss obviously thinks Her Majesty’s longevity has helped him dodge a bullet over the partygate affair, but I’m not so sure.

I receive a call from an old Oxford drinking chum, Hector Walmington-Curbishley, who now acts as a freelance security “adviser” to the House of Saud, several small African machine-gun republics and the Cortez drug cartel in Colombia.

“Roops, old chap. I heard you were back in town. What say you and I meet up tomorrow somewhere louche and discuss some photographs I have in my possession? Shall we say 11am at Panenka’s, the new Bohemian deli on Leicester Square?”

TUESDAY

I HAVE little choice but to meet with old Warmers. He is a charmless worm of an individual who makes Michael Gove seem noble. His family have a long history of seedy high-jinks among the flotsam of the English aristocracy.

His father, Walter, was the chap who procured the pig’s head into which dodgy Dave Cameron was compelled to place his John Thomas during that drinking game at the Bullingdon Club.

Rumours persist that the family pile in the Cotswolds was paid for by assorted bribes connected with other malfeasances committed during that raucous evening, of which Cameron’s porcine encounter was by no means the most eye-watering.

Warmers wastes no time in getting down to business. He produces an A4-sized brown envelope from which a handful of colour photographic prints come tumbling out.

Put simply, if Pippa Crerar ever got a hold of these snaps, she could syndicate them across the world and buy a small island in the Caribbean on the proceeds.

A sequence of three of them show a very familiar and high-profile personage using a delicate part of his anatomy as an aide-de-sniffoir for an unnamed companion to ingest a white powdered substance.

Another shows the PM wearing a Kiss-Me-Quick hat on all fours as he tries to place a balloon between Rishi Sunak’s legs in the style of the old 70s party game. This certainly does not look like “a necessary part” of a leader’s job.

But the worst is yet to come. It’s a two-minute-long video tape, complete with sound. It seems to be a very high-ranking member of our armed services handing over what looks like a sheaf of documents clearly marked top-secret to Vladimir Zinfonia, the Russian Embassy deputy chief.

You can clearly hear him say: “And to be clear then, Mr Zinfonia: you won’t do anything until we give you the green light to do so…?”

Whatever it was they were discussing doesn’t look good.

“So, I’m assuming you’ll be wanting some sort of recompense to make these pictures disappear,” I ask Warmers with barely concealed contempt.

“Business is business, Roopy, old chap. And spare me your contempt. Save it for these popinjays. I want £10m in my account by the close of business on Friday. And papa and I want seats in the royal box at the Platinum Jubilee concert this weekend. Failure to comply will see these being delivered to Ms Pippa Crerar by special delivery.”

WEDNESDAY

I PLACE a Union Jack tea towel on my toilet window ledge. It’s the signal to Colonel Olaf that we must meet urgently at our pre-agreed location in Regent’s Park. And that it’s a matter of national security.

I quickly appraise the colonel of the seriousness of the situation and that it must be taken care of within 48 hours. He responds with a look that says that the old but unremarkable aristocratic line of the Walmington-Curbishleys is about to come to an abrupt end. We agree terms that include the colonel and his team getting a nice fat slice of the repair work on the new Elizabeth line on the London Underground.

THURSDAY

THE news at 10 squeezes in a last item. “In breaking news, police are trying to put together pieces of the bodies of Hector Walmington-Curbishley and his father, Sir Walter, after they appeared to have been trampled and eaten by pigs during a stampede at their farm in the Cotswolds.”