The rail regulator has opened an investigation into whether Great Northern and Thameslink line operator Govia Thameslink breached requirements to keep passengers properly informed amid the May 2018 timetable rollout.

The Office of Rail and Road is investigating Govia and another franchise operator, Northern, over whether they did “everything reasonably practicable to provide appropriate, accurate and timely information to passengers in the run-up to the May 2018 timetable and during the disruption that followed”.

The action comes after the ORR’s timetable inquiry last month identified concerns with information given to passengers on Northern and Govia Thameslink’s Thameslink and Great Northern services.

Specifically, the ORR is investigating whether the two companies breached condition four of their Statements of National Regulatory Provisions – which requires train companies to provide “appropriate, accurate and timely information to enable railway passengers and prospective passengers to plan and make their journeys with a reasonable degree of assurance, including when there is disruption.”

The ORR has said it aims to conclude its investigation before the end of November, and that the companies could face action such as financial penalties if either is found to be in breach of its licence obligations.

In a letter to Govia Thameslink managing director Patrick Verwer, the ORR’S Stephanie Tobyn asked the company for submissions to its investigation by close of business on Friday, October 12.

A Govia Thameslink spokesman told this paper the company would “co-operate fully with the ORR’s investigation”.

The ORR’s three-month inquiry into the May 2018 disruption found that Network Rail, Govia Thameslink, Northern, the Department for Transport and the ORR had all made mistakes that contributed to chaos on the rails – particularly on Govia Thameslink and Northern.