BBC presenter Louis Theroux will spend a week inside the head of London mayor Boris Johnson as part of his new series. The daring challenge represents “the most extreme experience yet” for Louis, who is “partly apprehensive, partly very excited” about the opportunity.

“It’s somewhere no one has ever been,” he admitted yesterday. “Not even Boris, perhaps. What I’m particularly looking forward to is just getting in there and being a part of his mind for a full week, getting into his daily routine and finding out what makes him tick. Yes, I know it’s dangerous, and there will be a squat team ready to pluck me out of there if it gets too surreal, but I’m hopeful that I’ll last the week.”

Theroux plans to enter Boris Johnson’s head alone, and hopes that he will be able to spend some time with the Scousers and the Papua New Guineas that inhabit the mayor’s head: “I think if we’re going to understand Boris, we’re going to have to understand the many people that inhabit it.”

Psychologists say that implanting Louis Theroux inside the head of Boris Johnson could result in lasting, if not permanent mental damage. Pumice Cerveaux from the Zurich Institute for the Mentally Insane (ZIMI) said that Theroux may not last a full day, never mind a week:

“Boris might seem an affable, fluffy kind of fellow, but deep down, inside that brain of his, we can only speculate just how treacherous conditions may be. If Louis were to reach the inner sanctum of Boris’ mind within the first couple of hours, then he may either encounter a complete absence of stuff – a total feeling of emptiness – or he may encounter what at first appears to be an evil cross between Monty Python and the Carry On series.”

“On the other hand, he might be able to work out what’s going on, and finally answer some of the great unknown questions, such as why Boris is so fond of those routemaster buses. Whatever the result, scientists around the world will be watching this keenly.”

Boris himself was “totally up for it”, proclaiming with sweeping gestures: “Br-br-br-bring it on, I say! I’m totally up for it. Heck, I have no idea how they plan to put Louis in there – pr-pr-probably shrink him or something. Lumme! I can’t wait. Louis is going to have a great time in there. I’m sure he’ll encounter a few demons, a few skeletons and all that, but this is the new politics. Openness. All that. Great stuff.”