A third railroad union rejects proposed contract, further raising the odds of a strike

The chances of a railroad strike have gone up, after a third rail union rejected a tentative labor deal.

Rank and file members of the International Brotherhood of Boilermakers voted against a tentative agreement reached in September. I.B.B said it expects to continue negotiating.

The union, which represents about 300 workers, is the smallest of 13 unions that represent more than 100,000 union members at the nation’s major freight railroads. If any of those unions strike, its picket lines would be honored by the others. That could happen early next month and it would shut down a vital link in the nation's supply chain.

Congress could prevent or end a strike by extending a cooling-off period during which the unions cannot strike or by imposing a contract on union members.