SOUTHERN Railway and Thameslink have been named among the worst train operators in a new customer survey.

Issues of overcrowding, dirty trains and difficulties with complaints were all highlighted by passengers in Which? magazine's fifth annual questionnaire.

Some 1127 Southern, Gatwick Express and Thameslink customers questioned rated the companies among the worst for delays with an average of two stars (out of five) for punctuality, value for money and cleanliness and no higher than a three in each category.

Southern was rated with an overall customer satisfaction score of 48 per cent and Thameslink - which also includes the Great Northern service which it owns - as 46 per cent.

The companies said the figures needed to be taken into context of other surveys.

The news comes as the magazine launches a campaign to make rail refunds easier. Yesterday morning it spoke to commuters outside Brighton Railway Station with Hove MP, Peter Kyle, to raise awareness of how to complain and claim compensation.

Mr Kyle said: "When passengers are already at their wits end due to train delays or cancellations, the last thing they want is a long drawn out and confusing system to access the refunds they are entitled to.

"Quite frankly it’s time rail passengers started getting a better deal."

Richard Lloyd, Which? executive director, said: "Our report shows that Brighton’s commuters are getting a raw deal from their train operators.

"Rail operators need to do much more to treat their customers fairly, providing better information and access to compensation when passengers are delayed."

A Govia Thameslink Railway (GTR) spokesman, on behalf of both providers, said: "The Which? survey of fewer than 1,200 passenger journeys has to be seen in the context of the 1.1 million passenger journeys made on GTR every weekday.

"The recent National Rail Passenger Survey showed a much higher satisfaction rate. However, what both surveys show is there is still much to do to meet our passengers’ expectations.

"We know passenger satisfaction is strongly linked to punctuality and together with Network Rail, we are working hard to improve performance by reducing the delays within our control.

"However, there is no quick fix for the constraints that the rebuilding of London Bridge has put on our busy network, which means any incident quickly results in a domino effect on other services.

"We will however, continue to do everything within our power to provide our passengers with a better service, including providing better information to passengers during disruption and continuing with the country’s biggest ever driver recruitment and training programme."

How to claim compensation

BOTH train companies offer compensation with the Delay Repay scheme.

Passengers are compensated for any delay of 30 minutes or more regardless of the reason, although campaigners claim this is unfair on those who experience short delays frequently.

Southern Railway said claims for compensation have increased year on year which showed more people are aware of the scheme.

To apply, use the mobile phone app, visit social media or and see posters at stations.