It's a normal day at the pub in the King's Head Theatre. Waistcoated critics chortle at the bar and young actors throw darts, while older ones sup spritzers and point to their photos on the walls. But who's the chap in the middle scowling into his pint?

Thirty-six-year-old Mark Bromley is a window cleaner, but he's not washing today. He has written a pair of plays, and he's here to direct them. “I've got a ladder and a bucket and two days a week I listen to music and clean windows,” he says. “The sun's out - lovely. It could be very lucrative, but I don't want any more customers. I'm thinking about my play now.”

Tales from the Terraces, a double bill, opens on Sunday. The King's Head, in Islington, had a high-profile reopening this month, and he insists that, although it charges for the venue, submissions are selective. So how did Bromley make it? “With enormous struggle, that's how,” he says, rolling a cigarette.

On the face of it, his story doesn't sound too bad. Bromley, who has been writing casually since he was 15, approached the Anvil Arts Centre in Basingstoke, his home town, in 2004 and got his double bill on stage for two nights, receiving positive reviews from the local press. A few years later he approached the King's Head and was well received.

Now, his production is to run for six nights. The first play follows a thirtysomething woman's sinister reminiscences of the 1979 FA Cup Final, while the second, a comedy, explores what happens when a player meets a fan on the train. Bromley is very proud of both. “One guy can moan and bitch, and another can lose himself in crack cocaine. I write to avoid that. I can't think of anything I'd rather do than write for eight hours, and I'm confident that people will like my work.”

So why the scowl? “I'm looking over my shoulder at the shipwreck I've left behind me in the past 18 months. My relationship has been stretched to the point where we have separated. I've severed friendships, and I've been short with my daughter. I'm drinking too much, smoking too much, I've lost an awful lot of weight. I've become obsessed with getting this on.”

He rubs a hand over red eyes. “And I'm flat on my arse financially.” To hire the theatre, Bromley had to raise £2,200, which he did through donations, a sponsored run and intensive window-cleaning. He is yet to pay the actors and has a 14-year-old daughter to support. “I want to do what I love doing, but I have no other means of income so I'll have to get up a ladder this week - and it's the most important week of my life.”

Bromley's livelihood depends on how many tickets he sells and on bringing the production up to scratch to attract an agent. “I want to give up window cleaning this year. I've had enough of struggling.”

He is the son of a decorator and a cleaner. As a teenager he felt that writing was out of his reach. “It was like literary masturbation back then,” he guffaws. “I wrote in my room, but you don't talk about it. When I ‘came out', people said I had ideas above my station.”

At 24, after a series of manual jobs, someone suggested that he go to college. He did, but after proudly graduating from Bournemouth University with a degree in script writing, found no work and eventually began window cleaning. His breakthrough came in 2004.

The following period is a sore point. He wrote two screenplays and tried to break into film. “Some influential people promised things and, well, they didn't work out.

“What gets me,” he says, sitting up, “is that Guy Ritchie - a one-trick pony - is swanning around making films, and he's not cleaning f***ing windows. I believe I have something better to offer, but I'm not given the chance,” he peaks before sitting back and grabbing his pint. “So I have turned back to theatre, it's more egalitarian.”

His dream is to find an agent, and have his second screenplay, Thirteen Houses, taken up. His hopes are pinned on these six nights. “I need it to count for something, this time,” he says quietly. “Because I don't want to be cleaning windows again this year, I really don't.”

Tales from the Terraces is at the King's Head Theatre, London N1, on May 4, 11, 12, 18, 19 and 26. Box office: 0844 4122953

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