Demonstrators with the Occupy Wall Street protest movement in New York City are facing an early Friday morning deadline to end their sit-in at a privately-owned park near the city's financial district, setting up a potential showdown with authorities.

The company that owns Zucotti Park, which is open to the public 24 hours a day, says the area has become filthy during the month-long occupation and needs to be cleaned. It says the protesters will be allowed to return, but they will not be able to camp out on the grounds day and night.

The protesters launched a last-minute clean-up effort on Thursday in an effort to convince the company to reverse its decision, but insist they will ignore the ultimatum. The company says it will ask police to arrest the demonstrators if they fail to leave.

The Occupy Wall Street movement began on September 17 with a small group of activists accusing Corporate America of fostering a growing economic divide between the wealthy and the poor and middle class. The number of protesters has grown with each passing day, capturing the attention of news outlets and inspiring similar demonstrations across the U.S.

The New York protesters have had a few confrontations with police, including a mass arrest of protesters marching across the iconic Brooklyn Bridge last week.