A plan to replace the nation’s busiest bus terminal has shifted focus to the facility’s existing site in the heart of the city after a previous plan to move it a block west encountered strong resistance from lawmakers.

Officials at the Port Authority of New York and New Jersey, which owns and operates the Port Authority Bus Terminal, said at Thursday’s board meeting that a consultant will finish a study on the existing midtown Manhattan location by the end of July, to be considered by the board at its September meeting.

The study will estimate how much it will cost. Moving the terminal has been estimated at roughly $10 billion. The Port Authority has dedicated $3.5 billion in its 10-year capital plan to the project and has said it will explore private financing.

If the plan for the current site is accepted as the preferred alternative, an environmental review would then take 18 months to two years, Port Authority Executive Director Pat Foye said.

The project has been mired in controversy over the last year as politicians in New York and New Jersey have feuded over where the terminal should be and how much the Port Authority should spend on it.

The 24-hour bus terminal is located in an area usually teeming with city residents and tourists, near popular spots including Broadway theaters, B.B. King’s blues club and the Madame Tussauds wax museum. New York lawmakers have said moving the terminal a block west would destroy the surrounding neighborhood and have accused the Port Authority of ignoring their input in the early planning stages.

The Port Authority has been working on plans for a new bus terminal since 2013 and held a design competition that yielded several finalists last year. Those older plans appear to have been eclipsed by the plan to use the existing site.

The terminal, which has connections to the city’s subway system, operates at capacity and serves roughly a quarter-million people daily, a number projected to rise by at least 30 percent in 25 years.

(AP)