British rail services are suffering from “widespread disruption” in the run-up to Christmas, as firms are having to run reduced timetables due to workers being off sick or self-isolating. The CrossCountry train company is cancelling dozens of trains each day, and has reduced the number of carriages of many trains that are still operating. The firm said it is “expecting widespread disruption” to its services this week. It advised passengers to “pull your journey forward to sooner rather than later to get to your end destination as early as possible.” The Avanti West Coast company also said: “The pandemic is unfortunately resulting in some staff shortages. We’re doing everything we can to run our full timetable but there may be some short-notice cancellations.” Greater Anglia said it has to “plan for our staff being affected” by the Omicron CCP (Chinese Communist Party) virus variant, adding that it is “already starting …