There was a time when Ray was happy cleaning windows street by street. He had an ordinary round, and with his bicycle and ladder he slowly worked his way up one side of the road and then back down the other.

Everything changed six years ago when he caught another window cleaner stealing one of his customers. Window cleaners are fiercely protective of their rounds.

'I told him in no uncertain terms to shift it and that this was my street,' says Ray, who is 33.

But the poaching window cleaner wasn't interested in Ray's round, just the one house in the street, which belonged to Carla Lane.

'He said he had made an appointment and he was her own personal window cleaner,' remembers Ray. 'I didn't even know the one at the end was Carla Lane.'

The two window cleaners got talking, and the upshot was that Ray agreed to buy out the other window cleaner's clients.

Ray says his 'eyes popped out of his head' when he found out how much the other had been charging.

'I quickly worked out I was wasting my time with the old round, charging pounds 3 a visit. I had seen the future,' says Ray.

Ray has since turned his traditional ladder-and-bike round into a professional service with a cast of clients that would grace any Royal Variety Performance. Not for him a casual call with ladder and dirty rag slung over the shoulder. It's all by appointment these days. He now counts among his customers Clive Anderson, Max Bygraves, Gary Kemp and Sadie Frost and King Hussein of Jordan.

Today he's still cleaning Carla Lane's old house. When she sold up she recommended Ray to the new owner - Ruby Wax.

And that's very much how Ray has built up the round. Celebrities, or more usually celebrities' housekeepers, tend to pass his name on because, as one housekeeper put it, 'he's very discreet'.

'I like Ruby. She treats me like a friend rather then the window cleaner. Once I came round and she was having a birthday party - instead of ignoring me she gave me a piece of her birthday cake.'

Ruby Wax, like Carla Lane before her, lets Ray inside her house so he can do all the windows. For about an hour he has the run of the place.

'My favourite room is her steam room. It's called Ruby's Retreat. It's the most luxurious bathroom I have ever seen.'

Celebrities are especially careful who they let into their house, says Ray: 'They have to trust you. It usually takes a lot of visits before they let me in to even fill up my bucket.'

The novelist Doris Lessing won't let any other window cleaner into her house.

'Once I got someone else to do my round. But she wouldn't let him in. He kept telling her I had recommended him but it made no difference,' says Ray.

Once inside the celebrity's home, Ray knows that whatever he sees he has to forget and whatever he breaks he has to report. 'Stick to those two rules and you can't go wrong.'

In short, Ray know his place, and this is what has allowed him to build up a formidable reputation as a window cleaner to the stars. When Dustin Hoffman came to stay in London a few years ago to play Shylock in The Merchant of Venice, Ray's name was passed on to Hoffman's sister who arranged for him to clean their house in Kensington.

'I had to provide my very best references for Dustin,' he says. 'I thought I would get a chance to see him, but although I knew he was in the house he kept moving rooms to avoid bumping into me.'

Good references go a long way in window cleaning. If King Hussein of Jordan lets Ray into his flat then other clients aren't going to insist on a letter from the bank manager or his old headmaster vouching for his trustworthiness.

'I try to get references from as many famous people as possible; it tends to impress my other clients,' says Ray.

But it's not references alone which have opened some of the most famous doors in London.

'I'm not a very talkative sort of person,' says Ray. 'I like to get the job done and then get out. I don't like hanging around. Half of the celebrities I haven't heard of, anyway. I thought Doris Lessing was just a little old lady until someone told me she writes books.'

Clive Anderson was one of his first clients. 'It was just an ordinary client living in his road who knew Clive and recommended me to him. I didn't know he was really such a serious person. I certainly had no idea he was a barrister.'

It seems that Londoners (rich ones, that is) welcome the services of a reassuringly expensive window cleaner who carries a mobile phone and takes bookings for his next visit.

Window cleaners who work the posh districts of Notting Hill and St John's Wood, for instance, are notorious for operating a casual service. No one knows when they are likely to appear next, or whether it will be the same person. Even so, without any credentials, youngsters can make enough money from a week's takings to fund exotic summer holidays.

But professionalism pays. 'I've charged pounds 80 to clean a large house with loads of filthy windows,' Ray says. 'People pay because they know they are getting a thorough, reliable service for the future.'

He charges Ruby pounds 40, and Max Bygraves pounds 25 for his flat in Victoria. 'I charged John Cleese pounds 55 for his two houses knocked into one. He was my favourite, but I think my prices were too high and he found someone cheaper. I did him every month; it was a lovely three hours' work.

'I couldn't help laughing when I first met him because it was like being invited into Fawlty Towers. He asked me why I was laughing but I couldn't tell him. He even used to give me a tip. None of the other celebrities has done that.'

Former Radio 1 DJ Gary Davies is another of Ray's clients who can still afford his prices. He charges him pounds 40 for his five-storey house in Belsize Park.

'I once walked into a bedroom when Gary was working for Radio 1 and saw someone who I thought was Gary relaxing on his bed listening to Capital Radio. But he told me he was Gary's twin brother. I still don't know to this day whether Gary Davies does have a twin brother. It's just not my business, even if it was Gary listening to the opposition.'

According to Ray, window cleaners should be bound by a code of ethics that would include knocking on windows before cleaning them: 'People seem to think that window cleaners are all like Robin Askwith in Confessions of a Window Cleaner. Well, it just doesn't happen. I do the windows of a high-class call girl in Hyde Park Corner where one of the rooms is done out like a medieval torture chamber. I treat her like every other client and she always pays in cash and nothing else. My clients just want a professional job and no hanky-panky.'

So, who is Ray's favourite celebrity client? That's easy.

'Kelly LeBrock's mum. Kelly's my favourite actress and her mum always likes talking about her and showing me pictures of her. My great dream is one day I'll turn up to clean her mum's window and Kelly will be there.'

(Photograph omitted)