Rail passenger complaints soared during the chaos caused by new timetables, figures show.
Northern and Govia Thameslink Railway (GTR) suffered an increase in the rate of complaints of 63% and 23% respectively between April and June compared with the same period last year, Office of Rail and Road (ORR) data shows.
Both firms saw services crippled on many routes when new timetables were introduced on May 20, with the number of daily trains cancelled reaching 470 for GTR and 310 for Northern.
The timetable change was intended to deliver huge benefits to passengers as a result of major upgrades to the network.
GTR chief executive Charles Horton announced his resignation in the wake of the disruption.
The ORR, which is investigating the chaos, published an interim report last month which warned of a “lack of clarity about roles and responsibilities” and stated that “nobody took charge”.
Northern and GTR were among 13 train operators which saw their complaints rate rise between April and June.
Other firms to suffer an increase include CrossCountry (up 40%), Great Western Railway (up 80%) and Heathrow Express (up 60%).
The average rate of complaints across all operators was 29.9 per 100,000 journeys, representing a 6.6% year-on-year increase.
The most common complaint category was punctuality/reliability at 22% of all complaints, up 1.3 percentage points compared with the same period last year.