Rail passengers have been warned to prepare for “significantly disrupted” travel into the New Year amid a wave of industrial unrest sweeping across the country.The Network Rail warning came as members of the Transport Salaried Staffs’ Association (TSSA) at CrossCountry staged a 24-hour strike from 9pm on Boxing Day as part of a long-running campaign for a guarantee of no compulsory redundancies, no unagreed changes to terms and conditions, and a pay increase which addresses the rising cost of living.