Christos Tsiolkas had been writing for years before his fourth novel, The Slap, propelled him to worldwide acclaim. The Greek-Australian author tells Hannah Stephenson about the pressure to pen another hit and how his personal experiences have influenced his new book, Barracuda.

Christos Tsiolkas's award-winning novel The Slap, which became a book club favourite and was longlisted for the Man Booker Prize in 2010, was always going to be a tough act to follow.

The story, in which a man slaps a misbehaving child who is not his own at a suburban barbecue, sparking recriminations among the eight people present at the event, forms a wider look at modern family and domestic life in contemporary Australia.

Tsiolkas, 48, had already written three novels and won several awards in Australia before The Slap, but it was this one which propelled him into the literary limelight and changed his life, he admits now.

Yet today, he seems philosophical about whether his latest novel, Barracuda - his first since The Slap - will be as successful, and in some ways it's been like writing a second novel, he says.

"The Slap was successful internationally so there was a level of scrutiny that totally took me by surprise, because I never thought I'd have that kind of success. Of course I was thinking, 'What do I do next?'

"But reaching middle age, I know that whatever happens I will be writing. This is very much my vocation."

Barracuda tells the story of Danny Kelly, a working class boy in Melbourne who gains a sports scholarship to a private school because of his swimming prowess.

He feels like an outsider among his privileged peers, and it's anger which fuels his determination in the water and his goal of becoming an Olympic swimmer.

However, when he melts down at his first big championships, coming only fifth, he learns about failure and has to remake his life.

"As the previous book was quite successful, I wanted to write about the emotions surrounding success and failure," says Tsiolkas, who lives in Melbourne with his partner Wayne, a cartographer.

When The Slap was made into an Australian TV series, sales of the book were further boosted and Tsiolkas found that he was finally able to afford to give up the day jobs he'd had throughout his writing career.

His working class parents, who both had factory jobs, had initially been concerned that writing would be a tough line of work to pursue.

"My success gave the people who love me a certain happiness. My father passed away just over a year ago. He had been so concerned about how his son was going to make his way in the world, so I was glad to have been able to put his mind at rest."

He's already had some interest from production companies keen to adapt Barracuda for screen, but it's early days yet, he says.

"There's always an element of a leap of faith when someone adapts your work. You want to use someone who is fascinated by the book. If that happens, it would be fantastic."

As with so many authors, Tsiolkas has had the pleasure of becoming famous without actually being a recognisable face when he's out and about.

"People have been really nice but I don't have to wear Lady Gaga big glasses," he says, laughing.

Of course, the money from The Slap has made a big difference to his life, although he's not extravagant. He's paid off the mortgage on an art deco house he shares with Wayne outside Melbourne and also has a studio in the city where he writes.

"I haven't blown it on cocaine," he jokes. "But for the first time, knowing what it's like not to worry about money is an amazing thing. It gives you an astonishing freedom."

Some of the elements of Danny are drawn from Tsiolkas's own experiences. He too is a keen swimmer (although not of Olympic standards) and is also no stranger to feeling like an outsider.

The son of Greek immigrants who moved to Australia in their twenties, Tsiolkas didn't speak English until he went to school and was the first person in his family to go to university (he studied at the University of Melbourne), where he encountered richer, more privileged peers.

"I couldn't believe how clear their skin was or how straight their teeth were. The other thing that struck me was their poise.

"You feel you're always saying the wrong thing and there's this whole language and code that you don't know about."

At university, he fell in love with his room-mate Wayne. They've been together for 29 years.

Throughout the novel, Danny struggles to come to terms with his own homosexual desires. While Tsiolkas 'came out' many years ago, he well understands his fictional character's emotions but was keen not to write a 'coming out' novel.

"For me, a long struggle was about reconciling masculinity and homosexuality. For a long time, I felt I didn't have the key to do that. I know what a struggle that is, and I want to write about it."

He recalls that he had problems telling his family that he was gay at the age of 19.

"I knew that I was an outsider and was going to have to choose a path that for a time was going to put me outside the family, but I didn't want to live a lie.

"My parents had come from a very different world to mine. They had come from a Balkan village. They had no education. They really struggled. World War Two came. The civil war came.

"They grew up with certain expectations of what it was to be a woman and what it was to be a man, and suddenly I was speaking this language of liberation and independence and they were looking at me like I was demented.

"I remember that at the point of 'coming out' I didn't know the Greek word for homosexual, so I had to use the Greek version of the word 'faggot' or 'poofter', because that was the only language I had.

"It was a harsh period for me and for them, but because my parents loved their child, that meant they had to start learning a language around sexuality that they never had before," he adds. "It wasn't easy and there were a lot of stops and starts, but in the end it made our relationship much stronger."

Tsiolkas is currently working on a book of short stories and reveals that he runs much past Wayne before it goes to his publisher.

"He's a remarkably good reader. There were six different drafts of Barracuda and he read every one of them."

Although they've been together nearly 30 years, they've never considered tying the knot in a civil ceremony. "He refuses to marry me," Tsiolkas quips.

"When we reached 40, we'd been together 21 years and we had a party in our back yard with all our friends and family. I don't think anything could be more special than that."

:: Barracuda, by Christos Tsiolkas, is published by Atlantic Books, priced £12.99. Available now