Thousands of subway and bus workers picketed Wednesday outside the Metropolitan Transportation Authority headquarters, escalating a contract dispute between the state-controlled authority and the nation’s largest transport local.

Chanting a barnyard expletive during rush hour in Manhattan, members of Transport Workers Union Local 100 directed ire at MTA chairman and chief executive Pat Foye over an unsettled labor contract that expired May 15.

The union represents about 40,000 MTA workers.

Foye has not confirmed that Donohue's descriptions of the MTA's positions are the contract offers, and Foye has said he won’t negotiate in public. MTA spokesman Andrei Berman did not immediately provide a comment Wednesday on the rally. About a half dozen MTA cops protected the lobby of the headquarters at 2 Broadway.

The MTA's deficit is expected to grow to almost $1 billion in four years, according to an analysis released last month by the Citizens Budget Commission.