In yet another chapter in the political struggle over Harvard’s attempt to purchase 90 acres of industrial Boston land, an environmental review agency informed the would-be seller last week that they intend to review the sale and could even stop it completely.

Two weeks ago, Harvard bid $75 million to buy the land—an industrial plot crossed by railroads and cut by the Turnpike—from its current owner, the Massachusetts Turnpike Authority, which is low on funds after pouring billions into the Big Dig.

The parcel, known as Allston Landing South, has been the subject of political wrangling for months, including recent protests from a slew of powerful politicians, who say they are concerned that Harvard would push the rail yard—which some say is crucial to the local economy—off of the land.

But two weeks ago, the Turnpike Authority authorized their chair to approve Harvard’s bid. Pending all of the paperwork, the deal seemed a sure thing.

But late last week, the state’s Executive Office of Environmental Affairs (EOEA) instructed the Turnpike to prepare for an environmental review of the land, which could potentially derail the deal completely, according to Katie Cahill, an EOEA spokesperson.

“Basically we would need to be assured that the [railway] link will be kept operational for as long as the state needs it to be,” Cahill said of the EOEA’s review process.

The EOEA warning follows closely on the heels of outcries from prominent political officials, including Boston Mayor Thomas M. Menino and the state transportation secretary.

Many have said that the parcel’s tracks—owned by the CSX Company—play a crucial role in freight transportation as the only major rail yard near Boston’s port.

EOEA spokesperson Cahill said that her agency needed evidence that the rail yard would remain as a crucial part of Boston’s port system.

The loss of the rail yard could also affect untold environmental impact in the surrounding area, she added.

“[If the yard is evicted] the stuff that comes into the port will have to be trucked out to Worcester [the next nearest rail yard], which causes its own traffic and pollution problems.”

The EOEA sent a letter to the Turnpike Authority late last week, requesting documentation on how Harvard could change the land if they owned it.

If the agency decides that the sale could cripple the railway at anytime in the future, the deal could be halted entirely, Cahill said.

Turnpike Board Chair Matthew Amorello, who received the EOEA’s letter on Friday, said he was unsure about how the review could impact the deal, and could not confirm that the Turnpike’s land transfers were lawfully subject to EOEA approval.

“I just looked at it and we sent it to the legal department,” said Amorello. “I don’t know what it means.”

Despite protests from powerful local officials, Amorello has remained steadfast in pushing for the deal, which would help the agency to pay for road improvements and toll programs.

He and other board members, point to CSX’s permanent “easement”—a guarantee of right-of-way on the land, as reason that the railroad company could stay in Boston permanently.

The railway also passes through a 48-acre parcel called Allston Landing North, which the University purchased from the Turnpike in 1997.

“Harvard has owned its other holdings in Allston for two years now, and nothing’s happened to the railroads there,” Amorello said. “The railroads there too are protected by federal and states’ statutes.”

But officials from several state agencies remain unconvinced, saying that Harvard could flex its financial muscle to convince CSX to move from the land.

“Harvard’s purchase of the property would give Harvard a financial incentive to induce CSX to leave the property,” said Dick Garver, deputy director for planning at the BRA, which has already overseen some of Harvard’s development in the Allston area.

Garver echoed Boston politicians in emphasizing the economic importance of the railway.

“It’s the link to the port, it serves local businesses, it carries products to local consumers at a lower price than can be done by truck,” he said.

Bruce Houghton, whose chemical company is adjacent to the land and uses the railway frequently, said that the railway’s loss would be a major blow to his company and other local businesses, partly because it would mean a greater reliance on more costly freight trucking.

“The key to all of this is not who owns it, but really what happens to that rail yard, and how does that affect the pricing of all goods, affect the competitiveness in industry,” Houghton said in January. “If there were no rail available it would substantially increase our costs, which I suppose we would pass onto our customers. If that happened to all the freight coming in, the cost of living in New England would increase to some extent.”

Local politicians have also criticized the deal as unnecessarily rushed and not transparent enough.

“We’re not saying don’t go ahead with the sale, but we just want to have a discussion with other transportation officials before that sale goes forward to fully realize what implications such a sale might have for the next hundred years,” said John Carlyle, spokesperson for Transportation Secretary Daniel Grabowskis.

“We’re not sure what the terms of [CSX’s] easement are,” he said.

“There’s a little curiosity out there as to why this process seems to be expedited,” Carlyle said, “and why its difficult to get meetings and even phone calls returned.”

A day before voting on the sale, the Turnpike board met privately with concerned officials to attempt to calm their fears, Turnpike spokesperson Steve Hines said.

“We have stated publicly that we will make ourselves available at their convenience and provide them with any information they need,” Hines said.

While Harvard says it has no plans for the land and has not officially met with interested officials, University officials say they are keeping close tabs on the deal.

“It’s a Turnpike process and we’re following it,” said University spokesperson Lauren Marshall.

“It’s a long term investment for the University,” Marshall said. “And in terms of changes of the use of that property, we don’t expect any changes in the foreseeable future, should the [sale go through].”

—Staff writer Alex L. Pasternack can be reached at apastern@fas.harvard.edu.