Rail operator Southern has been ranked as the worst in the country following a passenger satisfaction survey.

Only 69 per cent of passengers said they were satisfied with the company’s overall service in Transport Focus research published today.

The figure is a fall of nine percentage points from the last National Rail Passenger Survey (NRPS) in the autumn, taking Southern to the bottom of the rankings alongside Southeastern.

Transport Focus said the performance of the rail network had sunk so low that “simply getting on a train has become a struggle for some”.

Passengers travelling to work were particularly unhappy with Southern, which runs many of south London’s trains and stations, with only 57 per cent of commuters satisfied.

Just 35 per cent said the service offered value for money and only 53 per cent were satisfied with Southern’s punctuality and reliability.

Prime Minister David Cameron called branded the company’s performance “unacceptable” during Prime Minister’s Questions yesterday, when asked by Horsham MP Jeremy Quin about industrial action.

Mr Cameron said: “I condemn any industrial action that disrupts the travelling public and rail passengers will not thank the RMT for their recent unnecessary disruption.

"Frankly the performance of Southern Rail has been unacceptable and passengers deserve better.

"I can tell the House that we will be providing more generous compensation to passengers affected by the latest strike and the transport secretary will be announcing further details soon."

Anthony Smith, chief executive for Transport Focus, was critical of the number of delays and cancellations faced by passengers.

He said: “Many passengers are feeling the strain. As passenger numbers rise and welcome investment is put in place some passengers are having a difficult time with delays and cancellations making journeys stressful. Simply getting on a train has become a struggle for some.

“Passengers’ main need is for a reliable railway. Our latest NRPS results, in London and the south east in particular, clearly show that for many this is not happening right now. Passengers want their reliable railway back.”

Alex Foulds, director of passenger services at Southern, said: “We are disappointed but not surprised with these results. The survey was carried out after a prolonged period of poor performance due to the constraints of London Bridge.

“The effects of a new timetable introduced in December to improve performance were then lost amidst a series of infrastructure failures which severely affected punctuality and reliability during the survey period.

“These coupled with the after effects of Storm Imogen and two train failures in key locations made for a pretty miserable time for passengers.

“Once through this challenging period we did start to see performance begin to improve, although this has now been overtaken by the recent industrial action.

“We recognise there is much to do and we continue to work hard with Network Rail to improve the performance of our network and our plans to improve customer service on our trains and stations, should ultimately deliver a better experience for all our passengers. We thank them for their patience.”

Southern has been locked in a bitter dispute with the RMT union about plans to scrap conductor roles and replace them with ‘on-board supervisors.’ The company says staff in the new roles would be more “more visible” to customers, but the union claims passenger safety will be put at risk.

Virgin and Heathrow Express achieve the best passenger satisfaction results of 90 per cent and 91 per cent respectively.