Many hungry New Yorkers scanned the streets in vain for hot dogs, shish kebabs and ice cream as Mayor Edward I. Koch began enforcing a 5-year-old ban on food vendors on crowded city sidewalks.

A special police unit took to the streets Monday to see that licensed vendors follow the ordinance, which limits the time and location that food pushcarts may operate. But many peddlers had already pulled their stands off the sidewalks in protest, and said they planned to demonstrate at City Hall."Demonstrations will have no impact on us. None at all!" said the mayor. "I wouldn't care if they came with 20,000 stands (to City Hall). It will have no impact."

Police said they confiscated four of the polished metal pushcarts with colorful umbrellas during the first day of the peddler patrol. But some 600 carts disappeared from the streets as a small group of vendors gathered across from Radio City Music Hall to protest.

"It means I've got two kids and I'm out of work now. And the mayor doesn't give a damn," said Thomas Michaelides, who's been hawking hot dogs for 25 years, like his father before him.

Those looking for a cheap lunch found themselves going hungry or paying more than they'd like.

The mayor admitted the crackdown was a bit of political arm-twisting to get the City Council to pass a new law that would allow six vendors, chosen by lottery, to work each prime street block.