I'll tell you something about Manhattan taxi drivers. They haven't a clue about where it's at. And for ''it'' read anywhere beyond the most obvious tourist attractions like the Empire State Building,

Central Park, and Macy's. This is not unconnected with the fact that most of them are not Manhattan taxi

drivers at all. They are Iranian taxi drivers, and Colombian taxi drivers, and Haitian taxi drivers.

Sure, they know the basics. They know that the Bronx is up and the Battery's down. It's just the bits in between where the problem lies. This means that if you're an out-of-towner they tend to take you the scenic route.

Clint Eastwood summed it up beautifully in Coogan's Bluff when he asked his cabbie: ''Say, how many Bloomingdale's are there in this town?'' I once counted four - which is curious, because there is only one.

But last weekend, I won a watch. I found a cabbie who was part of a rare breed. He was as near as dammit to being a native New Yorker. Now 60 years old, he'd emigrated from County Sligo at the age of eight. And he was a handy man to know for, as you would expect, he was on first-name terms with the proprietors of every Irish bar in town. I counted 34 - which is curious, because there are a damned sight more than that. So we're driving along 45th Street, shooting the breeze as we go, and we pass a sidewalk hot-dog stand.

''Avoid them like the plague, me boy,'' says the driver. ''Because I don't know what they are selling but they sure ain't no hot dogs.'' Then he paused for thought for a second. ''Then again, maybe that's exactly what they are - hot dogs. Like 'woof! woof!' You get my drift?''

I laughed politely and took the point. Eating Rover was not on my personal menu. But there was an irony here. Because, though it would be a cold day in Hell before the cab driver would touch the pavement vendor's purvy, he was happy enough to concede that they had one big thing in common. And that was a mutual loathing for New York's mayor, Rudolph Giuliani. The man, you see, has got it in for both of them.

It is all part of the single-minded Giuliani's efforts to clean up (some would say sanitise) the city. To make it all cutesy and nice; warm and cuddly. To make it a place fit for non-smoking, healthy-eating, politically-correct heroes. In short, to take the bite out of the Big Apple; Gotham City with no go.

GIULIANI is on a quality-of-life crusade. And, to be fair, you cannot fault him for what he's done to date. The mayor has successfully tackled the city's once-terrifying crime rate, he's taken the notorious ''squeegee men'' (the guys who wash car windshields when they're parked at traffic lights) off the streets, he's targeted drug dealers, and he's homed in on subway panhandlers.

Along the way (and with a little help from a huge new Disney store), he has achieved the seemingly impossible - the gentrification of Times Square. Once an ugly, dangerous, square mile of lapdance clubs, strip joints, and massage parlours, it has now been transformed into New York's very own urban theme park - the only thing that's missing is the thrill rides.

But now, according to my Irish taxi driver, Giuliani has gone too far. He has trained his sights on the city's 12,200 cabbies. Hizzoner reckons they're too rude so he has introduced rules to ensure more courteous behaviour and - how shall I put it? - less adventurous driving.

The guys behind the wheel (being rude goes with the territory for them) don't like it . . . which is why they're taking industrial action.

And where do the hot-dog sellers come in? Well, the talk of the NY steamy at the weekend was the fact that Giuliani now has his beady eyes on them. With a kind of senseless pretzel logic, the mayor wants to clear them off the street corners.

They're a hygiene risk, he says (which is a fair enough comment bearing in mind my cab driver's warning). But they're also a key part of New York culture. As famous, in their own not-so-sweet way, as the skyscrapers above them, or the A Train beneath them.

But, more important perhaps, they are (like the Yellow cabs) a traditional occupation for recently-arrived immigrants who have not, as yet, managed to get a grasp on the English language.

However, when it comes to hot dogs, Giuliani might just have bitten off more than he can chew. There are signs in the city which suggest that New Yorkers are getting a little ticked off by their mayor's ''I know what's best'' attitude.

And the attack on the law-abiding street vendors might be too much for them to take.

After all, Manhattan-ites don't like to be told what's good for them. And Big Apple pie and ice cream Giuliani-style sounds just too good to be true.