Passenger complaints have soared in the 12 months since a Dutch firm took over the ScotRail franchise.
Gripes against Abellio have risen 38 per cent, with up to one in ten services under the company’s control running late.
The figures come amid an ongoing dispute between the firm’s bosses and union leaders over the issue of driver-controlled trains.
Robert Sampson, passenger manager for consumer watchdog Transport Focus, said: “It’s disappointing that the rate of complaints has gone up.”
Abellio ScotRail said it had “forged ahead with a major programme of investment” against “a backdrop of unprecedented disruption – planned and unplanned”.