A fleet of new trains that will bring thousands of extra seats into London are “on track” according to manufacturing bosses.

The Class 700 trains, which are being built by Siemens, will be used for passenger services between Bedford and Brighton and Wimbledon and Sutton from spring next year.

They will then be used on routes from Peterborough and Cambridge, which come through Knebworth, Welwyn Garden City, Hatfield, Brookmans Park and Potters Bar, later in 2016.

The new trains will arrive in the country from Siemens test centre in Germany later this year, before being handed over to train owner Cross London Trains, who will then lease the trains to rail operator Govia Thameslink Railway (GTR).

Steve Scrimshaw, managing director of Siemens Rail Systems in the UK, said: “The manufacture of the state-of-the-art Class 700 is fully ‘on track’. Six trains have already been completed and over 200 body shells built so far.

“The fact that we have made such quick progress is testament to our commitment to delivering this strategically important project.”

Charles Horton, chief executive of GTR, said: “These new Thameslink trains we’ll be bringing into service next year are going to transform journeys for our passengers, creating much-needed capacity on our busy commuter routes.

“This, with other exciting improvements we are delivering, will add 10,000 more seats on services into London.”