PORTLAND — As it prepares to fight a lawsuit challenging a new ordinance that bans loitering on street medians, the city is limiting enforcement of the rule.

Police will only act on the ordinance in cases involving people who are “openly and obviously impaired by drugs or alcohol and posing a threat to traffic,” according to a City Hall press release Monday.

Relaxation of the ordinance comes as the city agreed to an expedited, one-day trial in the lawsuit, scheduled for Nov. 19.

On Sept. 24, the American Civil Liberties Union of Maine and Boston law firm Goodwin Procter filed the suit in federal court on behalf of three Portland residents. The suit claims the ordinance is “overbroad” and violates the residents’ constitutional right to free speech.

The loitering ban, which took effect in August, was unanimously approved by the City Council, which viewed it as a public safety measure. But critics claim the law is a thinly disguised attempt to clamp down on panhandling.

Meanwhile, the city is preparing for trial in another high-profile lawsuit.

The Friends of Congress Square Park are suing the city after it blocked the group’s attempt to launch a citizens’ initiative that would tighten protections for open space in Portland.

The Friends’ complaint, filed in state court Sept. 25, says the group correctly followed the process for beginning the initiative. If successful, the initiative would place Congress Square Plaza and 34 other publicly owned properties in the city’s Land Bank, and expand the types of property protected by it to include “urban open public spaces.”

The Land Bank protects designated open spaces with environmental or recreational values from development.

But the city rejected the Friends’ attempt, saying that such a citizens’ initiative would conflict with state and city law, which gives the City Council exclusive decision-making power in fiscal and administrative functions.

The complaint calls the rejection “arbitrary, capricious, legally erroneous and unsupported by competent evidence in the record.” It asks the court to order the clerk to provide the petition forms necessary to begin the initiative.

The Friends would have to collect 1,500 signatures from registered voters to put the changes to a referendum.

The Friends have long opposed the pending sale of about two-thirds of the plaza to RockBridge Capital, the developer of the former Eastland Park Hotel on High Street. RockBridge plans to use the space to build a meeting and event facility that would adjoin the hotel, which is scheduled to open in December as the Westin Portland Harborview.

Oral arguments in the Friends’ case are scheduled to begin Thursday.

William Hall can be reached at 781-3661 ext. 106 or whall@theforecaster.net. Follow him on Twitter: @hallwilliam4.