Funding has finally been secured to bring new high-speed trains to a key London to Scotland route in a £2.7 billion job-boosting contract.
The Government announced that a total of 497 carriages for the East Coast line will be built at Hitachi Rail Europe's purpose-built factory in Newton Aycliffe, County Durham, creating 730 jobs.
The Class 800 trains will start running on the East Coast line in 2018. Hitachi is also building 369 carriages to run on the Great Western line from 2017 under a funding agreement reached in 2012.
Today's announcement finally paves the way for the long-running Intercity Express Programme (IEP) saga to reach a conclusion. It was as far back as February 2009 that the Labour government announced that Hitachi-led consortium Agility Trains was the preferred bidder for the IEP.
But a series of difficulties meant that the final contract-award decision was delayed for some time.
The contract to deliver the carriages has been agreed with Agility Trains, a consortium of Hitachi Rail Europe and John Laing.
As well as building the new manufacturing facility at Newton Aycliffe, Hitachi will construct maintenance depots at sites including Bristol and Doncaster, and is refurbishing and upgrading depots across the Great Western and East Coast lines.
Hitachi recently announced its plans to move its global rail headquarters to the UK, further underlining the confidence in the UK economy and rail market
Transport Secretary Patrick McLoughlin said: "We are building a world-class rail system and the IEP is a key part of that.
"These new trains will transform rail travel between many of the great towns and cities of England and Scotland. This deal is further proof that our long-term economic plans are on track, creating jobs and breathing new life into the UK's train-building industry."
On the East Coast line the new trains will provide significant benefits to passengers, with 19% more seats on each train, reduced journey times between London, Leeds, Newcastle and Edinburgh by up to 15 minutes, and improved reliability.
Alistair Dormer, Hitachi's global rail chief executive, said: "This is an important milestone in the delivery of Class 800 series trains for the East Coast line.
"Hitachi Rail has been working closely with the Department for Transport, train operators and passenger groups to design the new trains.
"We are delighted that the success of the programme to date has attracted interest by world-class financiers and we look forward to building these trains in our new manufacturing plant in County Durham."
In a separate announcement, the Department for Transport said that under a new agreement the Abellio company would carry on running the Greater Anglia franchise until October 2016.
Passengers are being promised more services and better-equipped trains on Greater Anglia which runs from London's Liverpool Street station to major towns and cities across Cambridgeshire, Norfolk, Suffolk and Essex.
The new deal will see more services between Cambridge and Stansted airport, while carriages on trains between London and Ipswich, Norwich and Colchester will be spruced up.
International transport company Abellio also runs the Merseyrail and Northern Rail franchises.
Campaign for Better Transport chief executive Stephen Joseph said: "Passengers will be pleased to see the East Coast line trains finally getting an upgrade, but many will feel the move is overdue.
"The average East Coast train will be over 30 years old by the time they come out of service in 2018. That the new trains will be built in County Durham is also good news. Both passengers and UK engineering are crying out for a long-term Government strategy for rolling stock across the whole network."
Mick Cash, acting general secretary of the RMT transport union, said the new intercity trains were being built in Japan and " shipped flat-packed to the North East, where they will be bolted back together".
He went on: "Any new jobs are welcome but if the trains had been wholly constructed in the UK we would have been looking at many thousands of skilled engineering posts right across the supply chain which would have helped secure the future of train-building in the nation that gave the railways to the world.
"We should also remember that this intercity fleet contract has been mired in delays and mismanagement and is years behind schedule."
He went on: "Yet despite that, the publicly-run East Coast Main Line, using some of the most ageing units on the tracks, is delivering the best and most cost-effective services anywhere on the network, hammering home the case for public ownership of our railways.
"It would be a major scandal if the beneficiaries from the long-delayed East Coast fleet upgrade were another bunch of spivs and rip-off merchants from the private sector."