Sources said that the executive board of Local 100 voted by a 3-to-1 margin to strike - but that the move was opposed by TWU International President Michael O'Brien.

O'Brien noted that the MTA made concessions on crucial pension issues - and said going back to the negotiations table would be far better than absorbing huge fines from an illegal strike, the sources said.

The union defied O'Brien, who refused to authorize the strike, but said he wouldn't stand in the local's way, sources said. The move means the local risks losing crucial legal, financial and other support from the parent union.

Now union leaders face possible jail time, as well as massive fines for Local 100 and its workers, under the state's Taylor Law.