A slate of service cuts that would affect nearly every bus, subway and commuter rail rider in New York moved one step closer to passage on Monday after the plan was approved by a key committee of the Metropolitan Transportation Authority.

The cuts would eliminate two subway lines, create more crowding on subways and buses, and reduce frequency at off-peak hours. Service on dozens of bus lines would be reduced or ended, and disabled riders would find it more difficult to get around.

The plan would, in short, strip back some of the advances to New York City’s transit system in the past decade, and the formal announcement on Monday stirred a chorus of complaints from the city’s politicians and transit advocates, who pointed fingers at Albany, City Hall and the authority’s management.

At issue is a financial shortfall of nearly $400 million that appeared nearly overnight, after the authority learned of sudden sharp drops in revenues and state financing. On Friday, a court ruled that the authority must also pay big raises to transit workers, adding tens of millions of dollars in expenses.

“I wish I could tell you that losing this amount of money in this amount of time does not have painful consequences,” said Jay H. Walder, the authority’s chairman. “Unfortunately, I can’t.”

Still, it would be June at the earliest before any of the cuts take effect, and the biggest disruptions, like the elimination of the W and Z subway lines and an end to free tickets for city students, have to be approved again by the board in votes next year.

And the agency is trying to juggle financing estimates that appear to be in flux, even as it must by law present a balanced budget by the end of the year.

Next year’s financing gap of $383 million, although severe, is slightly less pessimistic than initially thought. The authority learned last weekend that a state payroll tax for mass transit was projected to fall $100 million below estimates, better than the $200 million shortfall that had originally been predicted.

“If this budget were to get passed, it’s nothing but a plan,” said Jeffrey A. Kay, a mayoral appointee to the authority’s board. “There are many, many other steps and changes that will be made before things get implemented.”

Mr. Walder, in a brief meeting with reporters, acknowledged that officials hope to refine the plan as more information trickles in about next year’s financing situation.

“But I don’t want to leave you with the sense that this isn’t very real,” Mr. Walder added. “There are few other ways to look at balancing a budget hole of the magnitude that it is right now.”

Attracting the most controversy on Monday was a proposal to phase out free fares for more than half a million students who currently receive free or discounted rides on the transit system. Half the discount would be erased in September 2010, with the rest swept away by September 2011. Officials from across the city pounced, with Mayor Michael R. Bloomberg labeling the idea “unconscionable.”

But there appeared to be a bit of political brinkmanship at play. Leaders at the transportation authority were quick to point out that the program used to be fully financed by the city and state, which have reduced or limited their contributions in recent years. An authority spokesman, Jeremy Soffin, said that it was uncommon for transit systems to shoulder the costs of student travel.

Charles Brecher, research director at the Citizens Budget Commission, a nonprofit fiscal monitor, said that while cutting student discounts underscored the pressures facing the authority, it could also be used as an effective negotiating tool.

“It helps create the notion that other parties share some of the responsibility,” he said. “It’s not just a general holding out of the cup. It says, ‘If you, the city, would increase your share, we wouldn’t have to do this.’ ”

The mayor’s appointees to the board vowed not to support the elimination of student discounts.

The budget, which does not include a fare increase for 2010, will go before the full board on Wednesday.

Asked if he would characterize this budget as a “doomsday” scenario, Mr. Walder took a more tempered tack. “These cuts are unfortunate,” he said cautiously. “We have had to make very painful choices.”