MBTA officials drew fiery criticism Monday for weighing the use of private contractors to operate 60 new buses as dozens of union workers, lawmakers and labor advocates crowded a board meeting.

Over more than an hour and a half of public commentary at Monday's meeting, speakers slammed the potential privatization as a financial risk that will not improve performance or working conditions.

"Private bidders have no allegiance to the taxpayer or the bus passenger," said Sen. Marc Pacheco, co-chair of the Legislature's Joint Committee on State Administration and Regulatory Oversight, who was one of half a dozen senators to speak against the idea Monday. "At the end of the day, privatization only results in higher costs and lower-quality service."

T officials stressed that they have not yet made a decision to commit to an outside vendor for bus operation and that they are still exploring the costs and benefits.

MBTA General Manager Steve Poftak told reporters that because the 60 new buses will be added to supplement existing service, no operators will lose their jobs if the T does agree to a private contract.