The son also rises: How Rafe Spall conquered Hollywood

All the world's a stage? More like all the world's a trailer with coffee-coloured leatherette sofas, carpets and walls, stationed in a suburban car park – the second home of most film and TV actors. And Rafe Spall is a very, very busy actor right now, which is why I find myself interviewing him during his lunch break on the set of the Channel 4 sitcom Pete Versus Life – sitting in his trailer in a car park of an adult education college in Hayes, not far from Heathrow Airport.

These lunch-break-in-trailer interviews are rarely ideal – the actor wants to masticate not talk, and having been up since dawn, and repeating the same lines through rehearsals and endless takes that drain the life out of them, they'd also rather stare at those latte-coloured walls than at a visiting interlocutor. But Spall, I must say, is quietly and gently very accommodating. I don't think I saw him chew once, although the food steadily diminished on his paper dish. My wife would be very happy if I could learn that trick.

Lunch, as on most days, means a plate of salad and a Diet Coke, the 28-year-old actor having shed five and a half stone so that he stopped getting sent "young fat boy" roles and begun being considered as a leading man. "Because I was always a fat child, I got fatter and fatter and I ended up 18 stone and with a 40-inch waist," he says. "I was a young, fat actor for maybe two years and then I started getting sent parts for very fat people, and I thought I wanted to change this... I wanted the parts skinnier boys were playing."

The catalyst came in 2006 when Spall was turned down for the film of David Nicholls' campus comedy-drama, Starter for Ten, for his lack of lean. It's testimony to Spall's dieting, then, that he will be on our cinema screens next week in the film adaptation of Nicholls' One Day, playing Anne Hathaway's boyfriend. But more of that later, because I'd just suggested to Spall the conventional connection between over-eating and unhappiness.

"I don't think I was unhappy, no, I had a very happy childhood," he says. "There's nothing wrong with my thyroid – I was a glutton. I used to go to the shop and buy seven chocolate bars, I don't know why. But also there's a fat gene on the Spall side which I was unlucky to inherit."

Glad he mentioned the Spall gene, because I wanted to get at least part way into my interview without bringing up the subject of his father, Timothy Spall – one of Mike Leigh's favourite actors, and one of mine ever since he played Barry, the Black Country electrician bore in Auf Wiedersehen, Pet. It's a name that opened doors but inevitably also threw something of a long shadow.

"If you're a casting director you're going to be curious to see what Timothy Spall's son is like," he says. "But when you get in the door you have to have something to offer. I'm under no illusion that it hasn't been a help, but it's about converting your opportunities, isn't it?

"I'll probably always be 'Timothy Spall's son' and it's something I'm proud of. Maybe one day as well as that, they'll say of Timothy Spall that 'He's Rafe Spall's dad'."

That day might come sooner rather than later if the son continues to rise at his current rate. Not only has he filmed One Day, but also Anonymous, Roland Emmerich's costume drama-cum-political thriller that advances the theory that Shakespeare's plays were in fact penned by Edward De Vere, the Earl of Oxford – Spall playing Shakespeare as a "drunken, illiterate actor".

"I'll show you a picture of me as Shakespeare if you want," he says, scrolling through his iPhone and assuring me that: "I don't carry pictures of myself in character all the time but someone sent me this".

And very dashing he looks too as the Bard – or the pseudo Bard. But if two major Hollywood movies weren't enough, Spall has also just returned from Iceland where he's been filming Ridley Scott's blockbuster prequel to Alien, called Prometheus. "I play a scientist," he begins, before stopping himself. "I got given an e-mail about what I'm allowed to say about this and what I'm not allowed to say, but I haven't read it yet so I'd better be careful."

Does he perhaps have an alien burst out of his chest, I suggest, like Ian Holm in the original Alien? "No, but shit goes down. You know, I was speaking to another actor in it the other day and was saying, 'Essentially you go into acting because you're a film fan, so even Ridley Scott talking to you is a pretty amazing thing'. In fact, every time Ridley came over I couldn't help but say, 'Ridley Scott just gave me directions'. It's cool because he's back doing sci-fi, the genre he's made some of his best films at – you know, Alien and Blade Runner. It feels like being part of film history."

Spall is also playing David Morrissey's son in a movie called Earthbound, and here he is, on a dreary summer's day in outer-suburbia, shooting the second series of the Channel 4 sitcom Pete Versus Life, in which Spall's budding sports reporter has his hapless love and professional lives commented upon by a pair of TV sports pundits. Spall is only just finding the time to juggle all his work – this shoot having had to be closed the previous week while he dashed off to Iceland for Prometheus.

"It's getting quicker," he says of his career. "Certain things come along that change things, I suppose. Maybe it's coincidental, but since Anonymous, it doesn't take much for people to go, 'Oh, they think he's good enough to be in their film, then he's good enough to be in our film'. It's ridiculous, but I'm not complaining because it's all going really well."

Born into the sociable Spall home in Honor Oak Park in south London, Rafe (named after the title character of The Knight of the Burning Pestle, which his father played in a Royal Shakespeare Company production) is the middle child sandwiched between two sisters, the exotically baptised Pascale and Mercedes. Neither Mercedes, who changed her name to Sadie, nor Pascale, who went by the name of Janet for much of her youth, wanted to be actors themselves – the former currently running a fabric shop in nearby Forest Hill, the latter a nursery teacher.

"I've always taken a sort of pride in saying they're both not actors because the first question people always ask me is, 'Why did you become an actor? Is it because your father is an actor?'. It gives me some sort of solace that I've got two sisters who aren't. They never fancied it. Anyway, I think two's enough in a family. I think it would have been too much for my mother."

Spall's mother, as anyone who saw the recent BBC4 series Timothy Spall: Back at Sea, in which Rafe's parents sail their converted barge around the British Isles, will know, is Sadie – a calming influence, at least at sea, where her husband seems to exist in a state of permanent abject terror. Anyway, Rafe didn't tell his parents about wanting to become an actor, his father overhearing his 14-year-old son informing a friend of his ambition.

"Then he said, 'Would you like to audition for the National Youth Theatre?' and I said, 'Yeah' and he said, 'Well, learn a speech – a Shakespeare speech and come and show me it'. He's since said it was terribly nerve-wracking for him because he'd decided that if he thought I wasn't up to it, he'd tell me to save me from a lifetime of pain. So there was a funny moment with him sitting on a sofa with a glass of wine and me doing, 'O, pardon me, thou bleeding piece of earth' from Julius Caesar."

The National Youth Theatre was the making of Spall, taking him away from what he believes was a path leading to prison. At school, Haberdashers' in New Cross (alma mater of Fiona Bruce, Shaun Wright-Phillips and Katie B), he was bright but disruptive. "I ended up hanging around with really tough kids and getting into fights," he says. "My dad got really ill when I was at school so that was weird. I was 15 and my dad had leukaemia... but there's no excuse really – the buck stopped with me. I was just lazy and naughty and more interested in making people laugh than I was handing in my drama GCSE coursework."

In fact he failed his GCSE drama. "Brilliant, isn't it? I suppose I always knew I was going to be an actor – I had complete confidence in it, but it was a confidence that was based on nothing." A similar shock lay in store when he applied for Rada – the drama school where his father had excelled back in the 1970s – and was rejected. "I thought that was my destined course. My dad won the Bancroft Gold Medal at Rada and that was always on my front room wall. But then I got an agent and started getting roles at the National and the Donmar and the Royal Court and I thought I might as well carry on with this. And now I think it was a great thing for me not to go to have gone to Rada... it separates me from what my dad did, and it also gave me a three-year headstart from everyone else."

That three-year start saw Spall in small film roles in Shaun of the Dead, Kidulthood and as a football hooligan in Green Street, with TV parts in The Rotters' Club and The Lion in Winter. It has only really been since 2007, however, that his career has started to take off, acting with his father in ITV's A Room with a View, playing Frankie Howerd's partner, Dennis Heymer, in the BBC biopic Frankie Howerd: Rather You Than Me, and the Pre-Raphaelite artist William Hunt in BBC2's Desperate Romantics. And then earlier this summer, Spall really grabbed attention as the delinquent gangster, Jay Wratten, in Hugo Blick's The Shadow Line – a BBC2 thriller series that sharply divided critical opinion between those who thought it a work of great verve and originality and those who thought it pretentious and self-indulgent (and those, like myself, who thought it was all of those things).

"I seemed to personify that as well," he says. "People either loved what I was doing or they hated it. But it's the thing I'm most proud of what I've done. I know what I like watching in acting, I know what excites me – and it's people going for it. In no way am I comparing myself to them but I love Gary Oldman and Jack Nicholson and Daniel Day Lewis – they're big, big actors – and I saw this as an opportunity to give it some."

Almost as divisive as The Shadow Line is David Nicholls' bestselling novel One Day, which tells the story of Emma and Dexter, following their 20-year 'friendship' from their one-night stand at university through to middle age. I enjoyed the book. Beneath its gimmicky structure whereby Emma and Dexter meet up on the same July day each year, I thought Nicholls captured much of what it's like to be in your twenties and thirties. Others have thrown the book at the wall in exasperation at what they have seen as stereotypical characterisation – especially of Emma, the leftie Yorkshire lass.

Anne Hathaway, sporting as far as I can discern from the trailers (there had been no preview screenings as we went to press) a Renée-Zellweger-as-Bridget-Jones accent, plays Emma, hot young actor Jim Sturgess plays Dexter, and Spall plays Ian, the failed stand-up comedian who Emma settles for out of desperation.

"Ian's the boy she shouldn't be with but what's interesting about the part is that usually in romantic comedies the boy she shouldn't be with is an arsehole – so you root for her to break up with him – but you know Ian's a good guy."

Looking a tad Alan Partridge-like as Ian, Spall may no longer get the fat-boy roles, but he's not yet a conventional leading man – though at least two of my female friends have admitted to having a crush on him. Spall himself is wry about his looks. "Someone said, 'You uglied up for Ian, didn't you?' and I said, 'No. It's my face; it's just me'.

His own love life is far less tortuous than Dexter and Emma's. After a two-year relationship with the scion of another acting family – Trevor Eve's daughter, Alice Eve – he is now happily married to Elize du Toit, the tall, blonde, South African-born actress still probably best known as Izzy in Hollyoaks. "We got set up on a blind date. We kissed within an hour of meeting each other and we've been together ever since."

That was three years ago. They got married last August, and Elize having fallen pregnant on her honeymoon, they now have a 12-week-old baby girl – Lena ("like Lena Horne... or Zavaroni"). "I love it," he says. "It's what I've always wanted. My biggest ambition over everything is to have kids. It feels great. I'd love a big family. My dad had three kids by the time he was 26, so..."

It seems almost a pity to conclude an interview with Rafe Spall with him talking about his father, but he seems to have no such inhibitions. He is very proud of him – calling Spall senior "the best actor of his generation" – as well as being incredibly close. "I speak to him all the time – about three times a week, and we talk a lot about the business and how it works because he's a master of it, he knows all about it. I value his opinion over anyone else's – and when I'm in plays I find it scarier than the press to be in front of him.

"It's a delicious way to spend your life – it really is," he says, waving his hand around his trailer – although it's clear he's not talking about leatherette chair and carpet the colour of over-milked coffee. "When people ask me whether my dad encouraged me... Yeah, he did encourage me, but only because he's made a great life out of it."