Anthony McCarten had been living in London for only a couple of days before he realised his place in the scheme of things.

He went to see a play at the National Theatre and had tickets in the cheapest seats, so high up that you could see the actors' bald spots.

"I spotted an empty seat in a prime spot about three rows back in the stalls," he says, down the phone line from his home in Gloucestershire, "and I thought: 'I'll be having that'."

A professional playwright for more than 15 years, he correctly anticipated the approach of half-time and, before the stage lights began to fade, he was off.

"As I ran down the stairs," he recalls, "congratulating myself on how smart I was, I heard a stampede of feet roaring down the opposite staircase. When I got to the door of the stalls I was beaten by about 25 people. It told me everything I needed to know about the UK and about how early you had to get up in the morning to get a worm."

In a roundabout way, the experience inspired McCarten's new film, Show of Hands, since that's the story of struggle to beat a crowd.

McCarten was only 25 when he met Stephen Sinclair at New Zealand Playwrights' Workshop in 1987. The two hit it off and, over six weeks, wrote a comedy about a group of unemployed men who have a bright idea about how to earn a bit of money.

Ladies' Night, cleverly conceived as one half drama, one half strip-show, went on to become a smash hit at home and abroad. (More than 20 years later, it's still doing very nicely, most recently in Germany and Russia).

In 1998, the pair unsuccessfully sued the makers of the hit film The Full Monty, claiming their story plagiarised Ladies' Night. Since neither man, from that day to this, has said a word other than "no comment" about the matter, it is probably reasonable to infer that they did not walk away empty-handed: confidentiality agreements usually go hand-in-hand with decent payouts.

Anyway, McCarten worked on, turning out solid if unspectacular plays, including Weed, about a cash-strapped hill-country farmer who decides to grow dope among the gorse, and Via Satellite, about a dysfunctional Kiwi family which comes under the media spotlight as one of their number competes in the Olympics. With Greg McGee, he adapted the latter into his first film, which he accompanied to Cannes where he was offered two movies to direct.

"They were both going to be in the UK," he says, "so I thought I won't go back to New Zealand just yet. I'll take these meetings. Now, the nature of film meetings is that they roll on for years. They never stop promising you imminent start dates and the dates are like a receding horizon. Before you know it, it's been two years, you've bought a house, and a kid's on the way."

After 10 years away, he says he feels "like Van Morrison, too long in exile".

"When I come home it's like a drop in cabin pressure. I breathe easier when I step off the plane. It's still my home in every sense of the word and I come home as often as I can."

McCarten really was home this week, in the town of his birth, New Plymouth, for the Tuesday premiere of Show of Hands, his second feature film. Adapted from his novel of the same name, it's the story of two people, Jess (Melanie Lynskey) and Tom (Craig Hall), competing in one of those once-popular caryard contests where the person who can keep a hand on a car the longest gets to keep it. She's a solo mum, desperate to win for the sake of her invalid child; he's a bitter and bloody-minded bankrupt.

"It was initially planned as a TV movie. But I had ambitions for it to be a theatrical feature, because it's a whole different mindset, in terms of how you can deepen the characters - shooting for television is just sort of data capture, really."

The screenplay set the film in Lower Hutt, where a "hands-on" world record was set, but an offer of support from Venture Taranaki made it possible to move it up a notch. It still meant working smart. A schedule of 35 days was compressed into 24. Even shooting on digital video, the crew was run ragged doing 40 set-ups a day - twice as many as normal.

"The crew went pale when I showed them my [plan]," says McCarten, "but they were all extremely battle-hardened from Lord of the Rings and they were up to the challenge."

The film is quintessentially Kiwi but the novel, originally entitled Endurance and set in London, is the product of what McCarten calls "those experiences where there is such a cauldron of competition".

"Out of that comes the character of Tom, who says that there is one way to deal with human beings and that is to be harder and more uncompromising than they are."

By contrast, he says, Jess has always seen herself as a victim but she makes peace with her approach to life.

"She says: 'I could be like you but I don't want to because I would have to tolerate people's hatred'."

The underlying theme can only gain currency with time as more people move to cities. But McCarten suspects that the car-holding competitions may be a thing of the past.

"There was a competition in Texas that was going to be the basis of a Robert Altman film," he says, "in which one of the participants, after three days walked across the road to K Mart and bought a handgun and came back to the car yard and blew his brains out.

"It's a very dangerous concept to deprive people of sleep. You cannot predict how they will behave."

McCarten may be unique in the world as a novelist who adapts his work to the screen and then directs it.

"I'll leave you to make that observation," he says.

"I am feeling increasingly confident in all three areas. I didn't always. It's been a long apprenticeship. I've done two films and I only now think I'm beginning to get the hang of it."

Just as well. He starts shooting in March on his next - Death of a Superhero - about a 14-year-old boy dying of cancer, who is desperate to lose his virginity before he dies. He is, he says, close to signing an A-lister for the pivotal part of the boy's psychologist.

Other scripts - about the life of Stephen Hawking and the famous East v West 1972 world championship chess match between Boris Spassky and Bobby Fischer are "all written, ready to go" and the subjects, presumably, of some of these ever-recurring film meetings.

McCarten, I observe, is nothing if not prolific. His reply is one to gladden any writer's heart.

"You do three pages a day and it's amazing how they mount up."

LOWDOWN
Who: Anthony McCarten, director playwright and novelist
Past works include: Ladies' Night (stage), Weed (stage), Via Satellite (stage and screen).
What: Show of Hands starring Melanie Lynskey, Craig Hall, Stephen Lovatt and others
When & where: Opens at Rialto, Skycity, Berkeley, Bridgeway cinemas on Thursday