Chiltern Railways will reintroduce first class service on its London Marylebone–West Midlands route in spring 2026. Enabled by new Mark 5A trains powered by recycled vegetable oil, these five-carriage sets offer USB ports, smart air-con, bike storage, and digital screens. First class will feature spacious seating and enhanced connectivity. Advance ticketing begins December 2026, with on-the-day upgrades available during rollout.