Dublin city centre at 6 a.m. on a Sunday morning is no place for the squeamish - or the sober. Feeling like an extra in a remake of Alfred Hitchcock's The Birds, all around me fat gulls swoop down on the stinking overspill from public litter bins and carelessly tied refuse sacks. Pigeons peck furiously at burger bun remains.

In the eerie half-light, a circle of McDonald's drink containers with jutting straws appear to form a crown on top of a litter bin on Grafton Street. The only sound, apart from the birds flapping around and the occasional singing drunk emerging from the shadows, is the crunch of the extraordinary number of plastic cups underfoot.

And if this all sounds a little melodramatic, it pales in comparison to the burger wrapper wasteland of O'Connell Street after a summer Saturday night of al fresco dining around the various fast food emporiums and on the steps of the O'Connell Monument.

While most of us look forward to a spell of warm weather, the people who work Dublin Corporation's street cleaning shift when the city slows to a lull between 6 a.m. and 10 a.m. must pray for rain to keep revellers indoors. Some of these workers have witnessed almost every type of dirt, gunge and grime known to man.

One of them, Val Travers, says he has seen them all in one place - the bottom of the drained Anna Livia fountain, which is treated by some as a nocturnal public toilet. Beer and wine bottles, chicken and burger bits and an average of £3-£4 in copper coins, which are put in the poor box, are retrieved from its depths on any given summer weekend night.

The extra litter the summer brings can be the least of their problems. "People can be in high spirits when the weather is good or if it's a bank holiday weekend or after an event like a festival or a concert," says Liam Hendrick, duty co-ordinating inspector with Dublin Corporation's Waste Management Services, "and they think that everyone else should be too.

"We've had incidents where people try to grab the keys of the green machine out of the operator's hand. On a couple of occasions, our workers have had to defend themselves against members of the public.

"One of our men went to the assistance of a woman he believed was being attacked by her husband. When he stepped in, they both assaulted him. The workers have to be very patient with members of the public and often the best advice is not to get involved."

At 6.30 a.m. in Temple Bar, East Essex Street is submerged beneath what has become the bane of litter warden Frank Murray's life - promotional flyers for nightclubs and entertainment venues.

One of 20 full-time wardens in the capital, he says the problem gets worse over a bank holiday weekend, when there are more events on and an influx of extra bodies wandering the streets. He tut-tuts at the untidy presentation of the refuse sacks outside business premises all around us, an offence for which the maximum fine, if it goes to court, is £1,500. This is often little deterrent.

"Some write the fines off as expenses. The staff want to go home after a long night and they don't bother tidying up properly," he says.

There have been 7,000 prosecutions under the Litter Pollution Act 1997 so far this year and all but 300 of them were business-related.

Murray's powers are limited. Approaching individual members of the public with bellies full of drink can be tricky and often they give false names and addresses.

"Generally you know when they are giving you the wrong name but you have to take it. Some are tourists and if you fine them £50 for throwing litter on the streets the chances are they won't stick around long enough to pay it.

"How people react to you often depends on your approach. If they get aggressive you can get the assistance of a Garda, but that's only if there's one available."

Both he and Liam Hendrick are defensive about the press criticism levelled at Dublin Corporation's clean-up operation in the wake of the St Patrick's Day celebrations last year.

"People often expect us to wave a wand and make everywhere spotless and they can't understand when that doesn't happen," says Hendrick.

"We had beautiful weather on that St Patrick's Day. There were thousands of people on the streets and many of them hung around until the early hours. As soon as you'd clean one spot, it was littered again immediately. We needed a bit more time to get the place back to normal."

The day after this year's delayed St Patrick's Day celebrations, the Lord Mayor, Maurice Ahern, announced that £3 million was to be spent by Dublin Corporation on anti-litter measures over the next three years. The number of litter wardens would be increased to 32, and 2,000 extra litter bins are to be placed around the city. Currently in the city centre, 25 people clean the streets at night and 45 during the day.

Frank Murray believes that Ireland is a "throwaway society".

"In my last job I was a caretaker in a block of flats and people used to throw rubbish over the balcony. They know there is someone there who will clean up after them and they abuse it. You'd wonder if there was no one around to clean the mess if they'd be more careful."

One of his jobs is to catch people who dump domestic rubbish in public litter bins.

The source is generally traced back to apartment blocks with inadequate refuse facilities.

The vehicles and equipment needed to suck up the dirt, dislodge the grime and hose the vomit and urine are numerous.

Dublin Corporation owns 32 motorised pedestrian sweeping machines called Green Machines. Light and easy to manoeuvre, they are gradually replacing the traditional handcart and brush - although some argue that the old method was better suited to cleaning gutters and between cars.

They also have two gully machines, 62 large refuse freighters, 41 small blue motorised litter removal vehicles, 12 open-backed tipper trucks and 12 large vacuum cleaners.

The workers are kitted out for the dirt: they wear heavy-duty gloves for handling hypodermic needles, steel-toe capped shoes in case they kick or drop heavy objects, and reflective clothes for night work.

Hendrick would like to see more fast-food businesses take responsibility for the litter outside own premises.

"They are legally responsible, but often when you approach the person in charge they say 'It wasn't me, it was the last duty manager'. Considering the amount of money they are making, they should make more of an effort."