PORTLAND – Nearly half of Portland residents oppose the proposed sale of part of Congress Square Plaza to a development company for an events center, a poll released Saturday said.

The poll said 49 percent of the residents contacted oppose the sale, 34 percent support it and 17 percent aren’t sure.

The Portland City Council is set to vote Monday on whether to sell the sunken urban plaza to Rockbridge Capital, which owns the adjacent Westin Portland Harborview Hotel, currently being renovated.

By larger margins, according to the poll, residents said the sale price of $524,000 for the nearly 10,000-square-foot parcel is too low; support putting the sale proposal to a referendum; and believe there should be some protections in place to prevent public parks from being sold to private developers.

The poll, by Public Policy Polling of Raleigh, N.C., was an automated poll of 507 Portland voters, conducted Thursday and Friday. The poll has a margin of error of plus or minus 4.4 percent, PPP said.

The poll was commissioned by opponents of the sale of the plaza, said Stephanie Clifford, a spokeswoman for Baldacci Communications, which released the poll.

She said the opponents who commissioned it don’t want their names released and have not said why they oppose the sale.

Protesters, including members of Occupy Portland, moved into the plaza Friday night but agreed to vacate after police told them the plaza was closed as of 10 p.m. and they would be arrested if they remained. The protesters removed a couple of tents they had set up when they left peacefully about 10:30 p.m.

Several protesters returned Saturday and set up two tents.

“We won’t sell the park,” said Max Landry, who identified himself as a leader of Occupy Portland.

More than half — 56 percent — of those polled said the sale price is too low and 47 percent said the public should have had more input to suggest alternatives to selling the plaza. And 63 percent said that, regardless of whether they support or oppose the sale, the issue should be put to a public vote, while 29 percent said the council should decide, and 8 percent were unsure.

Respondents were also asked if all public parks in Portland should be protected from being sold to private developers and 53 percent said yes, while 25 percent said no and 21 percent weren’t sure.

Rockbridge Capital, which is based in Ohio, did not return a call or an email seeking comment Saturday.

Edward D. Murphy can be contacted at 791-6465 or at:

emurphy@pressherald.com