The next big drama on Manhattan’s West Side could pit Senator D’Amato against the last visionary project of Senator Moynihan.

That is the contention of a source who says Mr. D’Amato, the powerful former Republican senator from New York who has been a registered lobbyist for Madison Square Garden, has been spending part of his energies working against the Pataki administration’s proposal to transform the Farley Post Office building into Moynihan Station.

A little more than a year after defeating the Jets Stadium on the far West Side, the owners of Madison Square Garden, the Dolan family, are lobbying again in Albany, according to several sources. Madison Square Garden LP employs lobbyists Patricia Lynch, who was Speaker Sheldon Silver’s chief of staff, and Mr. D’Amato’s firm, Park Strategies LLC, according to state records.

Earlier this month Mr. Silver postponed a vote on the plan by the Public Authorities Control Board, which must give final approval for the transit hub. The $900 million project, named after Daniel Patrick Moynihan, who died in 2003, would create new train hubs for New Jersey Transit and the Long Island Rail Road, a new post office, and retail outlets just to the west of the existing Penn Station. Mr. D’Amato served across the aisle from Moynihan for about 18 years, during which the two were known to have a cordial working relationship.

Assemblyman Richard Gottfried, who represents the West Side, said Ms. Lynch was lobbying on behalf of the Garden when the Moynihan project was in front of the PACB two weeks ago. But he said it was unclear what position the Garden was taking on the plan.

“Exactly what they are advocating for in this process, in terms of pace or substance, I have not heard yet,” Mr. Gottfried said. “There could be other aspects of the deal, financial or otherwise, that MSG might want to slow down.”

Mr. Gottfried said that Mr. D’Amato would more likely be employed to lobby the state Senate and the Pataki administration, both big supporters of the Moynihan project.

The Dolan family fears that a green light for Moynihan Station could threaten a grander plan by developers Vornado Realty Trust and the Related Companies to move the world’s most famous arena inside the western half of the Farley Post Office building, according to sources familiar with the project.

In that more ambitious plan, the Dolans would stand to gain a new arena, abandoning their outdated current site, on top of which the developers would improve the existing Penn Station and build office towers. If the Garden move does not proceed, the Dolans might have to spend millions renovating their existing facility.

So far, Madison Square Garden has had a low profile in the plans to move their arena. In the developers’ presentations to selected public officials and civic groups, a Garden representative has not been present. A deal has not yet been finalized between Related, Vornado, and the Dolans, according sources familiar with the project.

If the Garden is seeking to slow the Moynihan project, that would seem to be at odds with the desire of Vornado and Related, two of the city’s most powerful developers, who have been named by the state to build Moynihan. In a joint letter to the Empire State Development Corporation last week, the CEOs of Related and Vornado said that the Moynihan project should move forward regardless of what happens to the bigger plan to move the Garden.

Yesterday, a spokesman for the developers, Bud Perrone, said that they were unaware of any lobbying activity by MSG about Moynihan Station.

Vornado and Related have said that it could cost around $1 billion of public subsidies to remake Penn Station. The initial plan has been hailed by city officials as well as civic and planning groups as a unique opportunity to improve Penn Station and remake the entire far West Side.

State officials say that simpler Moynihan Station should be the priority, and that the plan to move the garden should come later. They say the building of Moynihan Station would in no way preclude the larger plan and that they want a vote before the PACB soon, and a ground breaking on the station before the governor leaves office at the end of this year.

Mr. D’Amato’s son, Christopher, who works at the former senator’s lobbying firm, told the New York Sun that he would not confirm any projects that Park Strategies was lobbying on behalf of the Garden other than what was available in public records. The latest filing with the state’s lobbying commission from May and June said that Park Strategies lobbied on behalf of Madison Square Garden for “West Side Re-development,” the Javits Convention Center, and the West Side Stadium project.

The records show that Park Strategies has received about $5,000 a month from the Garden for the last few years. Mr. D’Amato has said publicly that he once received $500,000 for making a single phone call on behalf of a client concerned about a decision to be made by the Metropolitan Transportation Authority.

A spokesman for the Mr. Silver, Bryan Franke, said that the Mr. Silver had only “spoken” with the Vornado and Related, who had made a presentation about the plan to move the Garden, and Mr. Gottfried, who represents the district in question.

Mr. Franke said that Mr. Silver believes the only “complete plan” he has seen is the larger plan to move the Garden, and that is not the plan currently before the Public Authorities Control Board.

Madison Square Garden is no stranger to public debates. Last year, the Garden’s owner, Cablevision, spent an estimated $22 million in lobbying in Albany and New York City over the proposed Jets Stadium on the far West Side, according to Common Cause, a good government group.

A spokeswoman for the Garden declined to comment.