The ongoing dispute between Partners HealthCare, the state’s largest health provider, and a group of hospitals objecting to Partners expansion entered a new phase yesterday. Boston’s Health Policy Commission took up the case and heard from those for and against the proposed deal Wednesday.

The commission had already examined part of the deal allowing Partners to acquire South Shore Hospital. But the merger would also involve the acquisition of two hospitals north of Boston. Wednesday the commission decided they will share their findings on that aspect of the deal with Attorney General Martha Coakley.

The Health Policy Commission can’t block the merger, but their findings could ultimately affect the deal, which is currently under review by the state superior court.

Commission chair Stuart Altman invited interested parties to weigh in, noting that their  comments would help guide the commission as they prepare their final report for the Attorney General. 

Rev. Burns Stanfield of the Greater Boston Interfaith Organization urged the commission to remember what he called their “sacred” responsibility to the people of the commonwealth to try and control health care costs.

"We need smart, thoughtful responsible folks like yourselves," Stanfield said. "Now I know there are also smart, thoughtful people that work for health-care providers and we need them to weigh in as well. But crucially, they represent healthcare providers. You represent us."

The commission’s studies focus on the likely impact of the merger on cost, quality, and access to health care on the south shore and north of the city. Their findings don’t square with Partners' claim that the deal will bring health-care costs down and quality up.

Alan McDonald Sr., an executive vice president with Hallmark Health, which owns Melrose-Wakefield Hospital and Lawrence Memorial Hospital in Medford, defended the proposed merger, saying it would allow his organization to make long needed upgrades — and improve the quality of the service they provide.

"We would only be able to make the investment and justify it if we had a broader network," MacDonald said. "And so the question for us is, 'What should that broader network be?' Since Hallmark came together, we’ve had a substantial informal relationship with the Mass. General Hospital, particularly as part of Partners, and it was the one potential partner that was interested in putting the investment in."

Not everyone agrees: especially the newly formed coalition of competing hospitals including Beth Israel, Lahey Medical, Tufts Medical and Atrius Health, who claim the Partners deal with drive up health-care costs and lead to fewer choices for consumers. David Spackman, general counsel for Lahey Health, implored the commission to weigh in on all aspects of the deal when writing their report.

"Our plea to you is — to the extent to which you can think bigger — you are it," Spackman said. "You are the organization that the commonwealth has created to look at these issues. And so if you’re on the fence between ‘Am I getting too broad? Am I going past the report?’ I would ask that if you’re not quite certain, go broader."

The commission will submit its final recommendation to the Attorney General’s office by July 21.