Fears were raised last night that a �6bn project to improve train services to London could see direct trains from west Norfolk scrapped.

The Thameslink programme is aiming to provide more frequent, longer and brand new trains into and through the capital to reduce overcrowding.

The project will see new and improved stations as well as new track and improved signalling, and could see trains go from King's Lynn to Gatwick Airport from as early as 2015.

But South West Norfolk MP Elizabeth Truss is worried the improvement work could stop at Cambridge – leaving only a shuttle service to Downham Market and King's Lynn.

She said: 'This all comes down to the type of train that the project is looking to introduce because it wouldn't be suitable to go from King's Lynn and Downham Market as the platforms aren't long enough.

'A final decision hasn't been made yet, but I want to raise awareness of what could happen because it could have a huge impact for commuters or people wanting to travel to London.

'I will be working hard to make sure the upgrade will benefit the whole service and not just stop at Cambridge.'

Meanwhile, North East Cambridgeshire MP Stephen Barclay has said Department of Transport figures put the cost of extending the service to King's Lynn at between �60 and �80m.

He said: 'I am very concerned that once again investment in our transport infrastructure focuses on city to city transport and ignores the increased population growth in rural areas like north east Cambridgeshire.

'It is very disappointing that local people who have paid through their taxes towards the cost of Thameslink should miss out on the direct link to London and Gatwick airport.'

Colin Sampson, chairman of the Fen Line Users Association, added: 'There does seem to be quite a bit of doubt about whether or not there will be direct trains from King's Lynn or if people will have to change.

'King's Lynn, Downham Market and Ely will be fine if the trains stay at eight coach length, but there is a lot of talk about new 10 coach trains.

'If these longer trains are brought in then the driver could just keep the doors shut where there is no platform, but I'm not convinced that would happen.

'As far as we know, it's anticipated we won't lose any direct trains and we might even get two trains per hour all day. But when more details about the project are published over the next few years we will be able to have a closer look and make sure Fen Line users don't lose the current excellent service.'

In response, the government's minister for transport Theresa Villiers has said it is 'not anticipated' that the number of direct trains from King's Lynn to London will change as a result of the programme.