A smart card for rail commuters means season ticket holders can skip the queues and claim refunds if their train is delayed.

Rail commuters travelling with Great Northern and Thameslink can now use the firms' Key Smart card in place of paper season tickets at Cambridge and stations to King's Lynn.

Passengers can sign up online for the card, which they tap on a ticket gate or station validator to access their train, without needing to queue for a ticket.

Lost cards can be instantly cancelled and replaced, while repayment claims for delayed journeys can be submitted with the click of a button.

Thameslink and Great Northern customer services director Jenny Saunders said: "The extension of the Key Smart card is great news for our passengers on the route to King's Lynn and especially for the thousands at Cambridge who commute with us to London King's Cross and St Pancras.

"The Key Smart card is quicker than a paper ticket, more secure and passengers using it can opt in for automatically-generated delay compensation claims.

"This strengthens our modernisation of passenger services. We have already brought in over 2,500 extra commuter seats on new, air-conditioned trains between Cambridge and London and next year we'll be doubling the length of the trains to and from King's Lynn, relieving congestion on this popular route."

John Grant, chairman of the Fen Line Users' Association, said: "I'm pleased that Fen Line passengers can now use this much better form of payment for Great Northern train tickets, giving them greater convenience when travelling by avoiding the queues at ticket machines and offices." Platforms are being extended at stations between Lynn and Cambridge to allow eight coach trains to run to and from Lynn from next year. The move will help cut congestion on early morning commuter services, which can currently only operate as four coaches.

Longer-term, improvements to the Ely North junction, where four lines meet, have moved a step closer with the government's announcement it is drawing up a detailed business case for the scheme.