Borough President Marty Markowitz has 13 coveted parking spots in traffic-congested downtown Brooklyn - but that hasn't stopped him and his staff from using the Borough Hall pedestrian plaza as an illegal parking lot.

The Daily News found up to 17 cars at a time parked on the flagstone plaza in the last three months - even though it's in the middle of Columbus Park, a city park.

"It is illegal for anyone to park on the pedestrian plaza around Borough Hall," said a city official who spoke on the condition of anonymity.

Markowitz's own black SUV is routinely parked on the sidewalk on Joralemon St. next to a busy newspaper kiosk amid a throng of pedestrians.

The News also found:

One of the regularly parked cars belongs to Markowitz's executive assistant, Deborah Brill.

Deputy Borough President Yvonne Graham frequently parks her powder-blue Jaguar on the plaza to the side of Borough Hall.

Markowitz's office prints temporary permits for certain visitors to Borough Hall to also park on the plaza.

"It's a hazard. Children run here," said Larry Johnson, 47, who dodged a green SUV Explorer registered to Markowitz's office as it crossed the plaza.

"You don't need a car," said Johnson. "There's a bus and train on every corner. They should be subject to the same tyranny as us, and park on the street."

The illegal practice was highlighted in a report this week by advocacy group Transportation Alternatives. The report chronicled widespread abuse by drivers with government parking permits.

The report named Markowitz's office among the top five city agencies that created dangerous conditions with their illegal parking.

Downtown Brooklyn is one of the city's most notoriously difficult places to park. When asked about the practice, spokesman Eric Demby said Markowitz was trying to free up street parking spots.

"Parking on the plaza has been standard practice for generations under several past borough presidents," he said. "We will investigate and work with the city to address the situation."

Still, residents were mad about the plaza parking.

"It ruins the beauty of the park," said Rene Brown, 44, of Flatbush. "Instead of parking cars here, they could have some benches."

Markowitz and five staffers continued to park on the plaza yesterday after being questioned by The News.