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

MONDAY

I’VE got a new job! The Perm Sec summoned me to his office today and said “we’re sending you to Scotland”. He insists that this is “a promotion”.

“The PM is getting increasingly concerned about the prospect of a second independence referendum in Scotland and doesn’t trust the information he’s been receiving from that Ross laddie. He feels that the best way to obtain quality intelligence is to establish a sleeper unit within the Scottish Government itself. And we want you to head it up. You’ll be given a generous budget to recruit suitable agents and to win the trust of Sturgeon and her top civil servants.”

“Yes, but how do you propose I do that,” I ask him. “I can’t just swan in to their parliament, kilt a-swinging and be given a job on the strength of my Scottish granny, the lady Moncrieff of MacDuff.”

“Don’t you worry about that, laddie. We have a high-ranking mole who’s risen to become an actual member of Sturgeon’s cabinet. You’ll get to meet him in time, but for now you’ll only know him only as ‘H’. He’ll secure a suitable Special Adviser’s job close to the First Minister’s office.

“There are also a few of our people who’ve infiltrated the SNP group at Westminster

“Your first task will be to rendezvous with him and establish a list of contacts and information drops. He’s a rum chap and will want to check you out personally, although you’ll be provided with a personally signed letter from the PM himself announcing that you’re serving at his pleasure and that you must be given every assistance.

“We’ve constructed a suitable CV for you which will establish your Scottish credentials and your passion for independence. A sum of £20k will be deposited into your account every month. Edinburgh rental rates are astronomical and you’ll be expected to dine most nights at the Balmoral Hotel, a very expensive establishment and one where most of our people are to be found most nights.

“If you succeed in this mission, laddie, you’ll get a gong and a Perm Sec appointment at the Foreign Office. But if you fail you probably won’t be coming back anyway, so it won’t really matter.”

Whatever could he mean?

TUESDAY

I OPEN the letter of safe passage which the PM has given me. It’s meant to provide me with a degree of comfort and security.

To whomever it may concern.

Rupert St John Fontaine is serving on a special project at my personal request.

He must be given every assistance in his pursuance of his quest, the nature of which is known only to me and him.

“The task on which he is embarked is of the utmost gravity and one on which the entire existence of our United Kingdom rests.

“If any unfortunate fate should befall Mr St John Fontaine while carrying out this mission the PM will disavow any knowledge of his work or of those who assisted him in it.

Yours, Indubitably and Entirely Without Consequence etc etc etc

Boris Johnson.

WEDNESDAY

AS I’m expected to start my new job quickly I must hurriedly arrange a farewell drinks party at Binky Martindale’s new wine bar in Shoreditch. It’s called Masopust with décor by the chic Belgian minimalists Van Himst and Van Der Elst and has already found favour with the minor royals who have their bar-tabs settled by Moscow-based property speculators eager to win influence.

As such, the place is usually hoaching with MI5 types who get routinely compromised in the palatial rest-rooms by Russian femmes (and hommes) fatale.

And then a curious thing happens halfway through the celebrations. There I am trying to break the party record for downing 20 Tequila Slammers (held by one B Johnson) when who should walk in but the Chuckle Brothers, aka Alas Smith and McDonald, aka Alyn Smith and Stewart McDonald, the SNP’s front-bench party boys.

“Hello Rupert,” says McDonald. “I hear you have a new job at Holyrood.” How on earth does he know that? I’ve only told my closest confidantes that I’m undertaking an academic sabbatical.

“I think we’ll be seeing a lot more of each other,” adds Smith, an inscrutable chap with a chilling smile that puts you in mind of the silver name-plate on a coffin-lid. Whatever could it all mean?

THURSDAY

I HAVE THE FEAR. And my dreams were haunted with images of a submarine. I’m standing on it as it’s about to dive, but I can’t get the hatch open and I’m being dragged down to the stygian depths of a dark, Scottish loch. As I try desperately to get to the surface all around me are mermaids who look like Nicola Sturgeon. I pull a sickie on Friday and prepare to travel north, troubled and perturbed.