Campaigners seeking to improve rail services across East Anglia underlined the need for new trains at a series of meetings with bidders for the new franchise for the region.

Joint chairs of East Anglian Rail Taskforce Chloe Smith MP and Mark Pendlington met representatives of the three groups bidding for the new long-term franchise which is due to start in October next year.

The bidders are First Group, National Express, and current incumbent Abellio in association with Stagecoach.

The government has already said that it will be looking for new trains to be introduced in the new franchise – a fleet of new InterCity trains to speed up services between London and the region is expected to cost in the region of £500m.

Norwich North MP Ms Smith said all the bidders had been made aware how important new trains were for the main line.

She said: 'The passengers are demanding this after years of putting up with older trains. The Chancellor and the Secretary of State for Transport have made it clear that new trains will be part of the requirements of the franchise, and we wanted to make it clear to them what is expected.'

What is not clear is whether new trains should be ordered for all lines – or just the main line between London and the region.

Many of the local diesel units are up to 28 years old, and the electric commuter trains are between 26 and 24 years old.

Ms Smith said the campaign would be pressing for new trains to be introduced on all routes in the region, not just the Great Eastern Main Line.

Mr Pendlington, chairman of the New Anglia Local Enterprise Partnership, said it was important that the campaign kept up the pressure.

He said: 'It is not the case that we sit down now and say 'They've got our message, now we can just watch all the improvements happen,' we shall be keeping up the campaign to make sure the needs of rail users are kept firmly in mind by the DfT and the bidders.'

As well as the estimated £500m cost of new trains, the taskforce is also hoping to persuade the government and Network Rail to commit to £476m of track, signalling and overhead wire improvements to the main line.