Jesse Armstrong on his first novel and writing fiction after 'The Thick of It' and 'Peep Show'

After co-scripting two major comedy hits, Jesse Armstrong thought he'd find writing a novel liberating. But going solo was a mixed bag of freedom and fear

Jesse Armstrong found he had a lot more creative freedom in writing a novel than he did working for television sitcoms (Geraint Lewis)

I'm a sitcom writer who has just written my first novel and for the last three years I've been experiencing the thrill and horror of being thrown out of the orchestra to become a soloist. Writing a sitcom compared with writing a novel is a bit like the difference between going on a big, noisy group holiday compared with a solitary march to the South Pole. On the one hand, the solo march is in some ways easier: you're in control, there are fewer people around with competing ideas. But on the other, during the solo march through the Antarctic, you are filled with quite a strong, all-pervading sensation that you are about to die.

"Is it how you imagined?" I've been asked this question quite a few times on the sets of shows I've worked on, such as Peep Show, Fresh Meat, The Thick of It, Black Mirror and Babylon. So what do you say? Well, you make positive noises. You say that it all looks amazing – it's all really, really great. Because, while you don't want to be a dick about it, the answer you don't really want to give, and they don't really want to hear, is: no, it's never quite how you imagined it.

The truth is that when writing a TV show or a film you are a part of a team. And though you might be the architect who makes the initial drawings, somewhere along the line it all has to be given up, handed over. To the costume department and the actors, the art department, the director and the producers. So on-set you stand around, a little in the way, shuffling out of the path of all the busy people with jobs to do, like a slightly bewildered grandparent at a family party, trying to look benign, smiling, confused at all this life you've begotten. You try not to go pursed-lipped and disapproving because it's different from what you imagined. Not, usually, worse. Usually, in fact, better – the script lifted by a great performance, a wise director's note, a clever use of the location, a perfect piece of costume or prop. But always different.

Freedom! Lovely freedom is what you get as a prose writer. There is no channel to limit your budget, to say no to helicopter shots or vast armies of Vikings or orcs; no volcanoes of chocolate. But this begs the question: do you want volcanoes of chocolate, really? If not, why not? Doesn't that sound fun? Ah, freedom! The freedom to swim out into the vast Pacific Ocean with nothing below you but a mile of cold blue water. Lovely freedom. This is the terrifying thing for a screenwriter coming to write prose. The horrible lack of restrictions. The absence of limits. A scene in a film or a TV show is a tight little ship. Your cast is set, limited. If you've created a decent plot, there is some problem to worry away at. There is usually what's called "a turn" to each scene. That is, something happens. That's what makes it a scene. Essentially, each beat in a plot is either a question, an argument or a resolution.

At first, sitting down to write a page of prose, I used to feel this dizzying sense of possibility. It was as though, after 20 years of being trained to run around a greyhound track, I'd been released for a scamper out of the back of a van into the Russian steppe. You look back, quizzically, as if to say: "What, I can go anywhere?"

Jesse Armstrong: 'Peep Show'

So the process of writing a novel for me was essentially about getting rid of as much freedom as possible. Restricting the action, tightening the focus. Building the frame for the roses to grow on. Settling on the tone, so you can exclude not just the orcs and the volcanoes of chocolate but the wrong observations, the incorrect jokes. My story is set against a background of real events, on a fictional trip into the Balkans in the 1990s. So my central task was finding the characters who were going to go on the journey and what was going to happen between them.

Sitcom characters, my writing partner Sam Bain and I sometimes tell each other, are not normally self-conscious. Or not quite. The best sitcom characters are probably just a little self-conscious. Deep enough to feel pain and humiliation, but shallow enough that there are no hidden depths. You can pretty much read across the faces of Basil Fawlty, George Costanza, Del Boy or even Hannah Horvath exactly what they're thinking. If they lie, conceal how they're feeling and we can see it, so much the better, so much the funnier. But you know pretty much their every impulse.

The Thick of It's star Malcolm Tucker told fictional minister Nicola Murray she resembled an 'omnishambles' (BBC)

Getting under the surface of real-life humans' poker faces humans is hard in a sitcom, even a drama. TV and film have tried lots of ways of displaying the fascinating stuff of the internal life. That is why Tony Soprano went to a room where he could talk about all the stuff he would never talk about, why Reggie Perrin had his graphic explosions of visual tourettes, why the documentary crew roamed Wernham Hogg. And it's why, as two people who met on a prose-writing course, Peep Show has been such an enjoyable show for Sam and me. Mark and Jeremy have interior monologues. They are allowed to be self-conscious sitcom characters.

That can be the very stuff of the novel – the internal world, the disjuncture between how we feel and how we act, what we want and what we do, what we think and what we say. So that part of writing comic prose was familiar enough to me. It's essentially the same field of jokes we've been harvesting in Peep Show for 10 years or so.

The other big thing that separates a TV show from a novel is a quite complicated technical one that I would summarise thus: a novel is way long. Even a short one like The Great Gatsby has around 10 times as many words as there are in a half-hour TV script. That is a lot of words to wrangle. The only way to attack it is slowly, a few hundred extra words per day, not worrying about the whole beast. Just behaving like a horse, eating only what's in the nose-bag in front of you. So it grows, in small daily accretions. But terrifyingly so. After a few weeks, writing just 500 words or so a day, you look back and there it is, transformed into something substantial, something slightly menacing, following you around, like a great unexpected tail you've grown.

It's as though you've been working on little bits of Plasticine each day, goofing around, tossing them over your shoulder when you're done. Then one day you look around and Frankenstein's monster has assembled itself out of your daily noodlings. But it's not Frankenstein's, it yours. When you look it over, you know every square inch. You can see your thumb prints everywhere. Thrillingly, but also sickeningly, it's just yourself.

So, my novel's finished and hitting the shops, and writing it has been heaven and hell. Heaven on the days when everything is flying, the plot is clear ahead and the characters are talking so loud and clear I just have to transcribe their words and note their feelings. Hell when it gets sludgy and sticky and I write pages of stuff which I half-know as I type I will be deleting tomorrow. It's heaven to know mine is the final word, and hell, too. No one to lean on, to ask for another idea, to shoot it all over to on a Friday night and say: "I'm done. You take a look. "

'Love, Sex & Other Foreign Policy Goals' by Jesse Armstrong is published by Jonathan Cape