Hundreds gathered outside a Parks Department hearing on the proposal, chanting "Artist power" and holding signs that accused the city of harassing artists. Inside, protesters occasionally disrupted the proceedings with the same message.
The Bloomberg administration is proposing new rules that would shrink the vendor population by up to 80 percent in some areas of the city's most famous parks.
The administration says those areas have become too crowded, and even dangerous.
"There are places where there are so many vendors, you can't get down the sidewalk," Bloomberg said Friday on his weekly radio show.
There are typically around 300 art vendors operating among the four parks covered by the proposed rule. The regulation would cut that to a total of 81.
Central Park's restricted areas would be allowed a total of 49 vendors — nearly half of them in front of the Metropolitan Museum of Art, and the others between Columbus Circle and Fifth Avenue on the park's south side.
Union Square would get 18, Battery Park would get nine and the High Line would get five.
Artists say the proposed caps are unconstitutional. A federal appeals court sided with the artists when the previous administration tried to limit street art vendors.
"If you pass this rule, you're going to have to arrest us every single day," Robert Lederman, a leader of the artist opposition, told officials at the hearing.
Former Parks Department Commissioner Henry Stern, who now runs the civic website NYCivic and showed up at the hearing, and felt that the speakers on both sides were "mistating" the issue.
"It's not whether there should be art in the park," he said. "It's whether the Parks Department can set a reasonable system."
He also added that a lot of the work being sold by vendors were recreations of art work, something "you can find in a Times Square souvenir shop."
"Work should be original and should be the work of the artists who have permits," he said.
Artist Tenzan Wangtu, 47, who is originally from Tibet, has been selling his paintings in Union Square for ten years.
"[The Mayor] is trying to limit us and make more problems for us," said Wangtu. "It is our First Ammendment right to sell our art in public space. I have no other way to make a living."
The city said there would be no immediate decision. The purpose of the daylong hearing was simply to gather comment.