Amazon delivery drivers and Starbucks baristas are on strike in a handful of U.S. cities as they seek to exert pressure on the two major companies to recognize them as unionized employees or to meet demands for an inaugural labor contract.

Striking Amazon and Starbucks workers in California and elsewhere have long pushed for union contracts. The Trump administration is unlikely to be on their side.

Amazon workers at four California facilities will join their striking colleagues on the picket line Thursday morning after reaching a stalemate during labor negotiations.