Now, the annual shopping bonanza faces an additional threat from strikes that could disrupt deliveries, subdue online sales and deliver another blow to the slumping economy.Christmas deliveries, jobs at riskBut the picture could get worse again before it gets better, with disruption stretching beyond Black Friday and well into the holiday season.Network Rail’s chief negotiator, Tim Shoveller said that striking makes the “precarious financial hole” in which the company finds itself bigger and “the task of finding a resolution ever more difficult.”Drivers for Best Food Logistics, who deliver fresh food to restaurants including KFC, Burger King and Pizza Hut, have also voted to strike, according to a statement from the GMB Union on Thursday.No dates have yet been announced and a company spokesperson told CNN Business it is committed to “reach a way forward.”The Communication Workers Union (CWU), which represents striking postal workers, has announced additional walkouts on December 9, 11, 14, 15, 23 and 24, which could jeopardize Christmas deliveries.Protests due to take place between shifts at an Amazon warehouse in Coventry, England on Friday evening are not expected to affect Black Friday deliveries."