“As we have shared with your team, it is imperative that a limited portion of Summer Street near South Station is closed to traffic,” read the letter sent from the Massachusetts Bay Transportation Authority’s General Manger Phillip Eng to the city’s interim chief of streets, Nicholas Gove.

The T’s letter, dated May 15, goes on to suggest that the state is moving forward with the plan to close down that stretch of Summer Street with or without the city’s buy-in, with Eng stating that the letter serves “as notice that the MBTA intends to acquire the temporary right to occupy this portion of Summer Street.”

“The MBTA will continue to work with the City to secure a permit, which would allow the MBTA to withdraw this notice,” read the letter.

The city says not so fast, painting the letter as an “eminent domain” power move.

“The City opposes this inappropriate use of eminent domain to bypass the permitting process for roadways under local jurisdiction, and we urge the Commonwealth to withdraw the filing while plans are being reviewed,” said a spokesperson for Mayor Michelle Wu’s administration in a statement.

The city’s agencies, according to the spokesperson, “have extensive experience managing major events of comparable scale, and the City has proposed alternatives to meet the safety and security needs of the World Cup while preserving access to this area for residents, visitors, and local commuters.”

The statement continued, “Full closure of a major route into the City for multiple entire workdays should be undertaken only as a last resort, and the City will continue working toward a resolution.”

The MBTA expects about 20,000 fans to take trains from Boston to Gillette Stadium for each of the local World Cup matches.

“Given the unprecedented number of people who will be coming to the South Station area to attend the World Cup, take their regular commutes or attend fan-related events, the MBTA has elevated its security posture in and around South Station to mirror those in place at [Gillette] Stadium on match days,” said Eng in the letter.

Boston city officials argue that the plan would further snarl traffic in an area that is already heavily congested during rush hour. They worry that planned detours for the closure don’t accurately account for driver behavior and that the proposal is underpinned by old data.

The city also says it has identified alternative plans that would not involve shutting down Summer Street, including utilizing Dewey Square and the Rose Kennedy Greenway as staging areas for passengers.

World Cup matches will be held in Foxborough on June 13, 16, 19, 23, 26, and 29, as well as July 9. The T plans to close down the street for stretches of 10 hours on game days, according to the letter. Previously, the T and the city agreed to shut down a portion of Summer Street for games on June 13 and 19, but Eng declared in the letter that “equal public safety needs exist for the other five matches.”

Summer Street is a busy thoroughfare that stretches from the city’s Financial District into the Seaport and South Boston. The stretch of road that would be shut down for World Cup game days is about a fifth of a mile, from South Station, a central commuting hub home to the Red Line, buses, and commuter rail service, to just before the Fort Point Channel. The intersection of Summer and Dorchester Avenue itself would not be shut down.

The move to close it down comes at the recommendation of State Police and the T’s public safety personnel, and local businesses have been apprised of the plan, according to the T’s letter.

“It is also consistent with steps we collaboratively take during other major events, such as First Night and the Boston Marathon,” said Eng in the letter.

Danny McDonald can be reached at daniel.mcdonald@globe.com. Follow him @Danny__McDonald.