A controversial proposal to transform a longtime auto body shop next to the Shawmut Red Line station into an apartment complex will move forward into a city review process with one less obstacle in its way.

The adjacent Epiphany School — which had openly floated plans to make a competing offer to buy the land in question — is backing off after Trinity Financial, Inc. detailed its rights in a letter sent by their attorney last month.

At issue is control of the Fitzpatrick Brothers auto body property at 150 Centre St. Trinity has a purchase-and-sale agreement to acquire the land from its longtime owners, whose family has operated a business there for more than 100 years.

Despite that agreement, leaders from the Epiphany School have approached nearby civic associations to seek support for their own idea to buy the property with an eye toward expanding the school’s campus. The latest declaration of that aspiration came at the July meeting of the Codman Square Neighborhood Council (CSNC), during which Epiphany leaders said they were prepared to make an offer to buy the Fitzpatrick property.

But Trinity, which has developed several notable properties in Dorchester including the Carruth and Treadmark buildings in Ashmont, had filed plans for review with city officials in mid-June.

Chris Stanley, Trinity’s assistant vice president of design and construction, told the Reporter this week that the company’s attorney had sent a letter to Epiphany following the July meeting, which was detailed in a story in the Reporter.

“The complicated piece Epiphany added to this is they were putting a development plan forward that they didn’t have a right to develop,” said Stanley. “We talked to our lawyers to see what we could do to protect our rights. We have the exclusive right to the property. The property owner said they wanted us to develop it and we have their blessing to move ahead.”

He added: “We wanted to make our legal rights known and asked Epiphany to please step out of the way while we go through this process. That’s our right and I believe they agreed to step aside.”

Wrote John Finley, Epiphany’s Head of School, in an email: “We have indeed received an email from Trinity's lawyer about this and have learned that Trinity has a (purchase and sale) with the Fitzpatrick’s to acquire 150 Centre Street. We respect that agreement and will not interfere with it.”

Epiphany said it has been invited to participate in the official Article 80 process run by the Boston Planning and Development Agency (BPDA), and that it has submitted a letter of opposition to the project as an abutter.

In his letter, which was accompanied by a petition signed by 95 neighbors and abutters, Finley cited the size of the building, and road easement issues that he claims could impact student safety, among other things.

“Like our neighbors, we believe transit-oriented residential housing on the site makes sense here, but not as currently proposed by Trinity Financial,” he wrote. “We are open to discussions for a development more sensitive to the scale of the surrounding neighborhood.”

Stanley said he hopes that Epiphany and other abutters will continue to be part of the process and have an open mind. He said he believes that he can persuade neighbors as to why this is a good project at this site.

“We have a very good track record at Trinity with our projects across the city – including the Carruth and the Treadmark,” he said. “I hope that offers evidence that when we talk about things, we deliver them, and we follow through on them…That’s part of the reason we wanted to make our intentions clear and unambiguous related to this property.”

Trinity is scheduled to make a presentation about the project— which includes 81 new units of rental housing—to the CSNC in September. It is also working on its expanded Project Notification Form to be submitted to the BPDA, Stanley said.