A rail firm says it is too early to say whether timetable changes have made its services more reliable.

Trains have been delayed and cancelled since Govia Thameslink Railway (GTR), which runs Great Northern trains between King's Lynn and London King's Cross, brought in a new timetable on May 20.

The Fen Line Users Association (FLUA) blamed a shortage of train drivers and extra stops which had been introduced after Cambridge.

Rail bosses hope a new interim timetable, which came into force yesterday, will reduce cancellations. Some stations will see a reduced service and special stop orders - where trains are made to stop at stations that are not part of the schedule - will only be issued during times of disruption.

GTR said the new timetable is an amended version of the May 20 timetable, which was designed to prioritise peak services and remove gaps wherever possible.

It said it had replanned its work schedules to make more efficient use of its drivers and be better able to match their route knowledge to the service.

It said that this was something it had not been able to do in the run-up to the May 20 timetable launch because the timetable was not approved until some three weeks in advance instead of the usual minimum of three months.

'The interim timetable should be more robust and reliable with fewer trains cancelled on the day over and above those removed in advance,' a spokesman for the rail firm said.

'It is too early to comment on this, its first day, but we will be focusing all our efforts on ensuring it beds in during the week.'

Extra compensation is also being offered to passengers most severely affected by disruption following May's timetable change.

It will be paid to qualifying season ticket holders according to the level of disruption experienced on Thameslink and Great Northern services.

GTR's website says: 'We continue to encourage all customers to claim compensation via our Delay Repay scheme whenever they experience a delay of 15 minutes or more and enhanced compensation where appropriate.'