Trains will run half-hourly between King's Lynn and London and new, air conditioned carriages will be phased in.

The new franchise set to run trains between King's Lynn has pledged thousands of extra seats on peak services to the capital.

The Thameslink Govia franchise will take over from First Capital Connect on September 14 and will also take over the South Central franchise, which operated as Southern and Gatwick Express, from 2015.

It will introduce half-hourly peak services between Lynn and London throughout the day.

It also says nearly 1,400 new carriages will be rolled out across the network, providing 50pc more capacity and 10,000 extra seats into central London during the morning peak by the end of 2018, with almost a third of them on the Cambridge - King's Cross route.

South West Norfolk MP Elizabeth Truss said the announcement by the Department for Transport was extremely positive for rail passengers and 'a real boost for future growth'.

'By having one rail provider, passengers should benefit from improved links across the whole Govia Thameslink Railway network but more importantly, the commitment of a half hourly service is extremely positive for rail commuters.

'With the extra seats, improved stations and ticketing, rail travel should become even more attractive

'Combined with the completion of the A11 works, the drive for full dualling of the A47 and continued investment in broadband, this is all a real boost to the area in terms of future growth for jobs, education, housing and tourism.'

Govia Thameslink, which will operate from King's Lynn to Brighton, has also been set new targets to improve punctuality by reducing delays by around a fifth and improve cleanliness.

Rail Minister Stephen Hammond said: 'New state-of-the-art trains, more seats, better connections and improved stations will transform travel across London and the south east.'