Despite the delays and cancellations that afflicted the first departures of the new Intercity Express Train, passengers, politicians and transport executives have welcomed the replacement for rolling stock that is four decades old.

On platform 10 at Reading station, waiting for the delayed train from Bristol to London Paddington, passenger Mike Bingham said: “It’s an important day. Going back 40-odd years to when they introduced the High Speed Trains, think how well they have last. If these can last half as well then that’ll be a great thing.”

Chris Grayling, the Transport Secretary, travelled on the first service from Bristol Temple Meads.

At London Paddington station, he told The Independent: “I think the train’s fantastic. A few teething problems but the reality is that this is going to transform Intercity rail travel in the UK - not just here on the Great Western line, but on the East Coast main line and the trans-Pennine route.

“What passengers really care about is having a smart, new train, high-quality wi-fi, lots of seats. This is the future of inter-city railways.”

In a £5.7bn contract, a total of 866 carriages are being made: 369 for the Great Western line and 497 for East Coast main line.

GWR, the first operator, says: “Whether they’re running on electric or diesel, state-of-the-art engineering means emissions and noise pollution are always kept to a minimum.”

The new rolling stock offers much faster acceleration than the current trains, as well as increased passenger comfort - with a mains socket at every seat - and capacity.

In the morning peak, the number of seats into Paddington will increase by 40 per cent.

Alun Cairns, Secretary of State for Wales, met the train at Paddington. He said: “So often the peak trains coming out of Paddington are jam-packed travelling all the way to Swansea. This will mean greater capacity and comfort, and it’s the first tangible benefit for passengers of a billion-pound investment in the railway.”

Network Rail’s Chief Executive, Mark Carne, said: “This is actually just one of the transformations of the network that people are going to see over the next 18 months.

“Great Western trains will have twice the number of services running from Bristol, 15 minutes faster journey times when these trains are running at full tilt, and then we have Crossrail, we have Thameslink, we’ve got Edinburgh-Glasgow electrification.