Train operator Southern has been ranked last for public trust in a new report on all the rail companies.
Analysis by watchdog Transport Focus showed the firm had notably low scores for trust in the last four passenger surveys.
The figures ranged from a dismal 17% in the spring and autumn of 2017 to 22% in the most recent poll of customers in autumn last year.
Southern has been engaged in a three-year dispute with the Rail, Maritime and Transport (RMT) union about guards on trains, which has resulted in industrial action.
The RMT has called Southern a basket case franchise and said it was not fit to run a railway.
The second worst performance on trust was by Great Northern with 24%.
That was followed by South Western Rail and Thameslink, both on 27%.
All three of these scores were recorded in the autumn 2018 survey.
Great Northern and Thameslink services were crippled by the chaotic launch of new timetables in May 2018.
Govia Thamelink Railway is the parent company of Southern, Great Northern and Thameslink.
RMT general secretary Mick Cash said: For over three years RMT members have been warning that Southern is a basket case franchise, cutting corners on safety and service and not fit to run a railway.
These latest shocking figures prove that we have been right all along.
The strongest trust performances were from Grand Central and Heathrow Express, who have consistently achieved scores of at least 70%.
Chiltern, Merseyrail and Virgin Trains all recorded ratings which did not dip below 60% over the four surveys.
Transport Focus submitted its analysis to the Government-commissioned Rail Review, which will make recommendations about the future of Britains railway.
The watchdogs chief executive Anthony Smith said: There are some wide variations between train operators that keenly reflect the passenger experience.