The first set of new 12-carriage trains on a busy commuter route ran today, with a Government minister helping to launch the service.
Rail Minister Theresa Villiers rode in the driver's cab on a First Capital Connect (FCC) train from St Pancras to Farringdon station in the City of London.
To the relief of FCC bosses waiting to greet her, Ms Villiers' train was bang on time.
But another Bedford-bound FCC train was 11 minutes late during the rush-hour - due to the late arrival of a crew member.
The 12-carriage trains were able to run on the Bedford to Brighton line due to the extension of platforms as part of the £6 billion Thameslink project which will be completed in 2018.
Passengers, including Ms Villiers, who arrived at Farringdon today were able to sample the new ticket hall, part of a massive transformation of the station which also serves the London Underground.
Ms Villiers said: "These longer carriages will make a real difference to commuters travelling on these busy routes.
"The Thameslink project is a key part of our massive programme of rail improvements."
The longer trains are providing FCC passengers with an extra 3,200 seats a day.
Ms Villiers was asked about a report that the commercial director of the East Coast train company - run in the public sector - took seven plane journeys last year between London and Scotland even though he could have used his own company's trains on the route.
Ms Villiers said: "I am not going to comment on personal travel arrangements. East Coast has put in a huge effort on this line and has been hit by problems, including cable theft. It's important that East Coast performance improves."