Complaints by passengers have soared at Southern after a year of industrial action in the dispute with guards.
The company – part of Govia Thameslink Railway (GTR) – has also been embroiled in a dispute with train drivers.
Yesterday the Office of Road and Rail (ORR) published statistics showing that the rate of complaints had shown a fourfold rise in a year.
The regulator said that GTR received 32.1 complaints per 100,000 passenger journeys in October, November and December.
In the previous quarter the figure was 31.6 while in October, November and December 2015 there were 7.2 passengers complaints per 100,000 journeys.
The company said: “These figures are disappointing but not surprising. This time last year our complaint rate was one of the lowest in the industry.
“Since then the onset of industrial action led to a sharp rise in the number of complaints. Now, as the performance of our train service improves, complaint rates are falling once again.”
Almost one in five passenger complaints across the country comes from people using GTR services.
But its complaints rate per 100,000 passenger journeys is still much lower than for other trains operators such as Virgin, Grand Central and Greater Anglia.
