Oyster cards could one day be valid along the whole Shoebury to Fenchurch Street railway line, according to train firm c2c.

The rail company announced the prepayment cards - more commonly used on the Tube - would soon be introduced along the line as far east as Dagenham Dock and Rainham, but it could be extended to more stations.

At the moment, terminals for Oyster cards are only installed between Fenchurch Street and Upminster.

By summer 2008, it is hoped passengers will also be able to use Oyster at Purfleet, Grays, Chafford Hundred and Ockendon stations, and a c2c spokesman said the long-term plan was probably to extend it along the whole route.

Spokesman Graham Bashford said: "I suspect that is the overall aim, long term, but we haven't got any definite plans. It makes it easier for people so encourages them to travel by public transport."

Oyster cards - topped up online or at stations - are pressed against a sensor at the start and finish of a journey.

Peter Slattery, co-chairman of Southend Rail Travellers' Assoc-iation, said extending the scheme would be welcomed, if people were able to buy their normal season ticket with an Oyster card.

He said: "My annual ticket has to be replaced three times a year as you have to put it through the gates.

"It fades because of the machine running against it. Oyster is much quicker.

"Two people with tickets get through the barriers in the time six people can with Oyster cards."