A Camden activist and three restaurant owners filed a lawsuit against the city Friday, claiming a business curfew set to go into effect next week is unconstitutional.

"It's economic freedom we're defending, the right of people to freely associate and buy and sell products," said activist Frank Fulbrook, one of the plaintiffs. "There have always been 24-hour restaurants in Camden. It's a part of life here."

The City Council passed an ordinance last month that would require restaurants and shops to close early in an effort to curb criminal activity around takeout food shops that stay open late into the night.

The Camden Police Department has made the case that drug activity and nuisance complaints are frequent at such establishments.

A hearing on a temporary restraining order is scheduled in Superior Court in Camden for Tuesday, one day after the ordinance goes into effect.

City Attorney Marc Riondino declined to comment on Friday.

Under the ordinance, restaurants and stores must close by 11 p.m. Sunday through Thursday, and midnight on Friday and Saturday, and reopen no earlier than 6 a.m.

Similar rules have been established in other parts of New Jersey, in communities as diverse as Newark and Collingswood.

Camden has tried to establish business curfews before, but pulled back following legal challenges from Fulbrook in 1998 and 2006.

While the business owners might be resisting, the ordinance has seen support from some residents.

At last month's council meeting one resident said she was tired of seeing drug deals going down in the shops.

"We are not a city that never sleeps," she said. "We are not New York City. We have to close down."