NEW YORK - A union representing 1,500 drivers for the disabled and chronically ill said a strike was all but certain Monday after management refused to meet for round-the-clock negotiations.

The Para Transit Drivers and Mechanics of the Amalgamated Transit Union Local 1181-1061 rejected a contract offer in the fall. Since then, the union said, management has turned down requests to resume talks.

“Rather than commit to collective bargaining, the bus companies have deliberately brought us to the picket line,” said Tommy Mullins, a union vice president and trustee of the local.

The union said it was prepared to strike starting at 12:01 a.m. Monday.

The drivers work for four companies that contract with the Metropolitan Transportation Authority, which runs the city's public bus and subway system. The MTA is not involved in the negotiations but is monitoring the situation.

Trips would continue to be scheduled, said Paul J. Fleuranges, a spokesman for the MTA's New York City Transit division. However, if there is a strike, transit officials will reassign trips and use other transportation providers and private ambulette carriers, particularly for serious medical trips such as dialysis treatment and chemotherapy, he said.

Some riders might qualify for taxi or car service vouchers, he said.