From a democratic socialist state representative to a federal prosecutor appointed by President Donald Trump, Philadelphia officials on Wednesday roundly criticized a plan supported by Mayor Jim Kenney to open the nation’s first supervised injection site in South Philadelphia next week.

City Council President Darrell L. Clarke went so far as to say he opposes the opening of any injection site in Philadelphia, a position he had not previously taken.

Even progressives open to using supervised injection as a tool to fight the city’s crippling opioid addiction and overdose crises were critical of Safehouse, the nonprofit formed to open the site, and the city’s handling of the announcement — scheduled to open just a week after a federal judge authorized it, without significant community input.

“I’m angry," said Councilmember Mark Squilla, a frequent Kenney ally whose district is just across Broad Street from the planned site. “It seems like their whole motto is to open it first and explain later, which is horrendous."

The reaction from elected officials from across the political spectrum reflects the obstacles Kenney faces in the first major fight of his second term, which began last month.

U.S. Attorney William M. McSwain has long been a vocal critic of Kenney’s plan for supervised injection sites, and has vowed to continue fighting to block such efforts. But on Wednesday, even many Democratic politicians stood on his side of the debate. Elected officials who represent South Philadelphia said they had been flooded with phone calls from constituents blindsided by the news.

Kenney said calls for a slower rollout would not have stopped opposition. He has supported Safehouse, but distanced himself Wednesday from the decision by saying that the nonprofit made it.

“At any point, you’re still going to have a controversy, wherever it is,” Kenney said.

Councilmember Maria Quiñones-Sánchez criticized the Kenney administration for using the nonprofit’s management of the project as a shield to protect the city against liability.

“What we’re doing with Safehouse is cowardly,” she said. “We’ve got to lead it, fund it, and not say, ‘this nonprofit,’ and we’re [hiding] back here."

Clarke took his opposition a step further than many. He said he would instead push for more access to treatment.

Even progressive politicians who have said they are open to the idea of supervised injection sites expressed concern Wednesday that the first location would open without community input.

» READ MORE: Philadelphia to get nation’s first supervised injection site: How we got here

Councilmember Jamie Gauthier said she agrees that the city should consider supervised injection sites.

“But I worry that we haven’t done enough to really inform and engage communities around the safe injection sites,” Gauthier said. “I think people are absolutely well within their rights to question the site, to question where it goes and to question what the impact would be in their neighborhoods.”

“Safehouse was beginning to build public support through a patient and transparent dialogue with Philadelphians before blindsiding residents with this bait and switch," said State Sen. Larry Farnese, who supported the concept. “Trust has been lost.”

Yet it was not clear Wednesday whether City Council or state lawmakers have any power to block or delay the opening next week — or prevent other locations in the city later.

Squilla and Councilmember Kenyatta Johnson, whose district includes the planned site at Constitution Health Plaza on South Broad Street, said they would review existing regulations.

Former Mayor and Gov. Ed Rendell, who is on Safehouse’s board, said he spoke with Johnson earlier this week.

“I said, ‘Look, it’s one of those things, Kenyatta. People fear it, but once it opens, I don’t think people are going to have a problem with it,’ ” Rendell said.

Democratic State Reps. Elizabeth Fiedler, Jordan Harris, and Maria Donatucci shared their frustration in a joint statement, saying Safehouse’s action has led to “anxiety and trepidation" in the neighborhood.

Kenney said talks are underway for a second site in Kensington, which is primarily in Sánchez’s district. That plan, however, could produce an even bigger row.

“It’s not happening in Kensington,” Sánchez said.

Staff writer Aubrey Whelan contributed to this article.