Recession, as seen by Tom Hanks and Julia Roberts

The highest-grossing star in the world and America's sweetheart can feel our pain, they tell Gill Pringle ahead of their new movie

He is officially the biggest box-office star in the world and she is America's long-reigning sweetheart and eternal Pretty Woman. As a screen couple, Tom Hanks and Julia Roberts perhaps don't quite enjoy the same coupling chemistry as they shared, respectively, with Meg Ryan and Richard Gere, but they certainly pack a powerful collective star-power. Co-starring today in the recession-themed Larry Crowne, a film also co-written and directed by Hanks, they ask audiences to suspend belief and imagine that they know something of lay-offs, budget-tightening and job insecurity.

"There have been times of doubt and fear, admittedly a long time ago," says Hanks, 54, the highest all-time box-office star with a more than $3.6bn box-office gross from hit movies like Toy Story, Saving Private Ryan, Apollo 13 and Sleepless in Seattle. "Quite frankly, and I'm going to guess for both of us," he says, as Roberts sits by his side, "there's been times where we're living in a house – a rented house in the Valley that we cannot afford – and we have been fired from the job that we had and it's now been 13 months since you've actually worked in the city and the phone still is not yet ringing and you wonder if, in fact, you're going to take the job at the Der Wienerschnitzel on Laurel Canyon," he says, referring to a well-known landmark fast-food place.

Roberts agrees. "And I had the New York version of that. I was selling shoes between jobs," says the actress, 43, whose big break came 23 years ago in Mystic Pizza. Two years later, Pretty Woman launched her on a remarkable career. With a fortune estimated today at more than $200m – and homes in Taos, Malibu and New York – she was the first actress to reach the $20m-salary mark in 2000 for Erin Brockovich, which also won her an Oscar.

For Hanks, the idea for Larry Crowne – a middle-aged man forced to enrol in college after he's laid off from his job – came decades before the current economic crisis, when he was attending junior college. "This was in the mid-Seventies, and there was a sensibility of flux," he reflects. "In my class there was somebody in their forties, somebody in his fifties, people with kids and somebody who was just back from Vietnam. I became friends with almost everybody in class, and I found this rich life-experience among them."

Refusing to insult the unemployed millions by pretending to truly understand their pain for the benefit of box-office bucks, he says instead: "Unlike Larry, I've never had all of my ability to make a living taken away from me or had my entire world crushed like that. I've lost gigs as an actor thinking that this is in development and I'm going to play it. I'm having meetings with it and it's all going to work out and we'll start shooting it in about three months... I've lost jobs like that but that's always for artistic reasons or something else comes along, the money falls apart or what have you. But there's not a person in the world that can't empathise with the idea of walking into a place that you think you're kind of like a king at and next, you're out there with all your possessions before lunchtime."

The film is also about second acts – something that neither Hanks or Roberts have required in their chosen careers, where they continue to be loved by millions, Roberts most recently in Eat Pray Love while Hanks – who won Oscars for Forrest Gump and Philadelphia – has diversified, becoming a prolific film producer responsible for such hits as Mamma Mia!, My Big Fat Greek Wedding and Evan Almighty between acting gigs. "I've been lucky," he says. "Man, I would be lost if someone said, 'You, you're out of show business.'."

Crowne blithely reinvents himself after losing his job, then Roberts's college teacher drowns in booze as a way of dealing with her feckless husband's addiction to internet porn. When asked if a spouse's penchant for porn-surfing – or any such bad behaviour – should necessarily be a deal-breaker in a relationship, the actress sighs, "I know, so picky, picky.

"I'm, luckily, happily married to a person that I admire and enjoy so it's not really fair to say or to conjure some kind of bad scenario that I wouldn't tolerate. I think people have their different ideas of what's good and what's happy in this particular scenario that Tom drew for me. But it was fun to play and Bryan [Cranston] is hilarious but, yeah, it's sad for both of them, the situation they've gotten themselves into in that house."

She was in Rome shooting Eat Pray Love when Hanks sent her the script. "The story was charming, yet topical, for so many of the characters who are losing faith and trying to cope by rediscovering themselves. I was intrigued by my character and her drinking problem. She has pickled herself into this cocoon of an unhappy life. She's in a position where her dreams are not coming to fruition the way she pictured them. She's given up a bit. I immediately called Tom back and said I would hitch my wagon to his."

While Roberts's colourful love-life once provided tabloid fodder, today she mostly escapes such scrutiny, wed nine years to cameraman Danny Moder with whom she has seven-year-old twins Hazel and Phinnaeus and son, Henry, four. Remarkably she looks every bit as radiant as she did two decades ago. Dressed in jeans, booties and a casual jacket, it doesn't even seem like she needs to work at staying lean in her forties, munching idly on a bag of potato chips. Having become close friends with Hanks a decade earlier, they finally co-starred in Charlie Wilson's War four years ago, a film also produced by Hanks.

Brutally aware of the bleak commercial prospects for Larry Crowne, up against a summer sea of superheroes, explosions and special effects, Hanks says, "But how do we compete in the marketplace? Forgive me, I haven't the slightest f***ing idea. The nature of the movies is different than it was five years ago and they are driven by the possibilities of CGI, which means you can make anything happen on screen that you can possibly desire. That's a great brand of freedom that is given over to the film-maker. But when you are going to try to have people talk in a room and actually reflect life as we know it and have people recognise themselves and their own street and their own house in it, well then you're aiming for the high country and so it's a much bigger gamble."

Anticipating critics who might see Larry Crowne as a rather glib comment on what is a very serious and depressing issue, he says: "At the end of this film, Larry lives in a crappy apartment, he can't even afford to pay his gas in his big car, and he's going to school with no real set future of what's going to happen. But he's got this amazing new forceful presence in his life and he can honestly say, 'the best thing that ever happened to me was getting fired from my job,' and that actually does happen in the real world, oddly enough."

Larry Crowne may be suffering from a mid-life crisis but Hanks, who turns 55 on July 9, assures us he isn't. "It's just the opposite; I'm embracing the whole thing because there's no way I'd want to be 44 again, much less 54. The concept of a midlife crisis is: a guy who has everything wakes up, [thinks] 'I have everything and yet I'm unhappy'. I've never remotely gone through anything like that at all."

Previously wed to actress Samantha Lewes, with whom he has actor son Colin and daughter Elizabeth, Hanks has been married to actress Rita Wilson for 23 years and the couple have two sons Chet, 21, and Truman, 16. Wilson even has a cameo in Larry Crowne, styled as a sassy blonde instead of her usual brunette, prompting him to laugh: "I said, 'baby, is there any way at all we could take that wig home at the end of the work day... can you just keep it on? Let me take it off later on.' I'm joking, but it's great we get to play at work. My wife and I, we met making a movie. It's not just our job, it's our life, it's what we do naturally, whether we're working together or not. "

It has been 15 years since he last sat in the director's seat for That Thing You Do, returning to the job today after Larry Crowne was rejected by major studios, forcing him also to finance the project.

"That's correct, no studio paid for this film. We sent it around to the two big-time studios that we have relationships with and both said, 'we do not know how to make a movie like this, so we can't do it'.

"I simply decided to do the film through my own company and take the better part of two years. I want to make a movie that's going to surprise people. I don't want to see escapist fare. I don't want to see dream-factory wish-fulfilment films about if you work hard, your dreams will come true. I want to see movies about human beings, adults that have gone through bitter compromise and are, in a glamorous and yet realistic fashion, living up to the challenges that the world presents to them. I think that's what Larry Crowne is."

'Larry Crowne' opens on 1 July