Union bosses have called for Southern to be stripped of its franchise after the rail operator came rock bottom in a nationwide customer satisfaction survey.

Mick Cash, the general secretary of the Rail, Maritime and Transport (RMT) union, called on the Government to terminate Southern’s contract after commuters gave it a one-star rating in a Which? survey.

It found only 21 per cent of commuters were satisfied with their service, 23 per cent lower than last year’s survey and 46 per cent said their last journey with Southern had been delayed in the report released on Tuesday, January 17.

Merseyrail came top with a customer score of 72 per cent.

The franchise was given one star for punctuality, reliability, seat availability, frequency and value for money and two stars for the availability and cleanliness of its toilets by the 2,000 surveyed commuters.

RMT general secretary Mick Cash said: "This Which? report shows that Southern Rail are the absolute worst of a bad-bunch when it comes to Britain's rotten, privatised railways. The responsibility for the catastrophic mismanagement of this crucial rail operation lies fairly and squarely with the Government and their contractors Govia Thameslink Rail (GTR).

"This scandal cannot be allowed to continue. GTR and their French-backers (Keolis-the largest private transport group in France) who routinely put private profits before passenger services and safety, must be stripped of this franchise with the public sector given a chance to sort this mess out once and for all."

A Southern spokesman admitted its performance was unacceptable and apologised.

He said: "Our passengers deserve better and, together with Network Rail and its £300m funding package, which includes improving track signalling, prevent trespass, building specific teams to coordinate upgrade work and improving drainage in old tunnels. We're working hard to improve the service.

"This survey inevitably reflects the significant impact of the industrial action taken by ASLEF and the RMT but we do recognise that performance was not good before industrial action began in April last year for which we are truly sorry.

“This was predominantly due to the on-going additional knock-on delays from the London Bridge redevelopment on Southern and Thameslink networks. Despite this, we are committed to working hard to giving passengers the services they expect and deserve."

The survey was released one day after Southern relaunched its bid to hire more trainee drivers to avoid further disruption from unions taking industrial action.

Southern is hiring to maintain a pool of 200 drivers and called its hiring campaign as the ‘UK’s largest’.