The Bloomberg administration, as part of a new invitation for bids to replace contracts expiring in June for 1,100 school bus routes, issued specifications ending some seniority-based job guarantees for drivers.

It claims that the unions, by seeking to extend the old contracts until the strike is settled, is holding the city and school children "hostage" over issues the drivers can only resolve with the bus companies. 

City Council Speaker Christine Quinn said that, if she were making the call, she would have agreed to a temporary extension to get the drivers back to work and the parties to the negotiating table.

The National Labor Relations Board has rejected an application by the bus companies to stop the strike, rejecting their argument that the bidders on the city's contract are caught in a labor dispute between the bus drivers union and the city.

The NLRB, in dismissing the bus companies' application, declined to call the strike unlawful, finding that both the city and the bus companies are "primary employers."

The bus companies vowed to appeal.

The article from the New York Times.