The Department for Transport (DfT) is to be investigated in connection with rail disruption following the launch of new timetables.
An inquiry launched by rail regulator the Office of Rail and Road (ORR) will look at the department’s role in “managing risks around major network changes”, its terms of reference state.
Hundreds of trains were cancelled or significantly delayed since many departure times were changed on May 20.
Govia Thameslink Railway (GTR) and Northern introduced temporary timetables last week, removing around 6% of daily services in a bid to boost reliability.
Transport Secretary Chris Grayling has blamed Network Rail for being “very late” to finalise the new timetables and a delay in completing infrastructure projects.
He also criticised GTR and Northern for inadequate planning.
In addition to examining the DfT’s role, the ORR will also investigate the actions of the train operators and Network Rail.
ORR chairman Stephen Glaister pledged to consider the issues independently and dispassionately.
He said: “While I want the inquiry to proceed at pace it is important to be thorough and impartial. We will collect evidence from a range of organisations, including passenger representatives such as Transport Focus, and be supported by an expert panel of external advisers.”
The inquiry will publish its initial findings in September with a final report by the end of the year.