Passengers on Southern Rail are facing continued travel misery as the latest strike by workers enters its second day.
Members of the Rail, Maritime and Transport (RMT) union have walked out for 48 hours in the long-running dispute over the role of conductors.
Southern plans to run up to 60% of its services during the industrial action, which the RMT said was "solidly supported" on Wednesday.
The Office of Rail and Road is due to release quarterly figures showing the number of cancelled and late trains.
Travellers using Southern Rail have suffered months of delays and cancellations as the dispute rumbled on, and a temporary timetable was introduced with 341 fewer trains on July 11 following "unprecedented" sickness levels among train crew.
The Government announced last week it was setting up a £20 million fund aimed at resolving delays on Southern.
Meanwhile a rail passengers' group has announced it is planning to fund a legal review of the Government's handling of the franchise.
The Association of British Commuters, set up earlier this year because of the Southern problems, said it will work closely with lawyers to compile evidence of people losing their jobs because of cancelled trains, as well as the disruption to home and family during the chaos.