Couples will still be able to book a twin berth for £30 each, but all single passengers will have to pay £40 - or £80 for a return journey - to have a berth to themselves. Currently, the company's sleeper carriage can accommodate 24 people sharing twin berths. Under the new rules, it could provide beds for only 12 people travelling alone.
First Group, the parent company, is also considering an end to allowing strangers to share on its London-Scotland sleepers.