Extending London to Birmingham HS2 line to cities in the north of England is designed to cut journey times, ease overcrowding and boost regional business and create at least 100,000 jobs. I
However the next stage of the £32.7 billion project is likely to face fierce opposition from rural communities through which the line will pass and also the chosen location of stations.
According to the Department for Transport there will be five stops on the 211-mile Y-shaped extension northwards from Birmingham - scheduled to be completed in 2032, six years after the first phase.
The planned stops are:
- Manchester - alongside the existing Piccadilly station;
- Manchester Airport - interchange by the M56 between Warburton Green and Davenport Green;
- East Midlands - at Toton, between Nottingham and Derby and one mile from the M1;
- Sheffield - at Meadowhall shopping centre;
- Leeds - at New Lane in the South bank area connected to the main station by walkway.
There will also be a "dedicated link" alongside the high-speed line at Crewe to link up with standard trains - reducing journey times to Liverpool and Glasgow.
But a proposed spur to Heathrow has been put on hold pending the results of Sir Howard Davies' review of future airport capacity - which is not due to give a final report until the summer of 2015.
Instead passengers heading to the world's busiest airport will have to change onto the new London east-west Crossrail service for an 11-minute transfer to terminals.
The journey from Manchester to Birmingham is set to be reduced to 41 minutes and from Manchester to London to 1 hour 8 minutes - almost half the present times.
Leeds will be 57mins away from Birmingham compared to 1hr 58 mins today, and 1hr 22mins away from London Euston, down from 2hrs 12mins - official projections say.
Critics have suggested that siting the Sheffield station outside the city centre - requiring passengers to take a connecting train of around 7-12mins - will mean standard trains will get people there more quickly.
The project has been welcomed by many civic and business leaders in the region.
But the first tranche proved controversial, especially in picturesque Tory heartlands which will be affected, such as the Chilterns, infuriating MPs and countryside campaigners.
Residents there will not enjoy the economic or personal benefits of a station and some have opposed the project on environmental grounds - a pattern expected to be repeated this time around.
The High Court is considering whether the first phase of the project, which will take high-speed trains from London to Birmingham, is legally flawed and needs to be reconsidered.
The challenge was taken to the court by campaigners who accused the government of failing to undertake a "strategic environmental assessment" or arrange an adequate consultation process.
Labour backs HS2 - which was begun under its administration - but says there are "worrying signs" that the timetable for delivering it is slipping.
Shadow transport secretary Maria Eagle said: "We believe ministers should be working more vigorously to ensure the proposals are delivered on time."
The "botched" consultation on the first phase may have to be rerun if the High Court upholds the campaigners' cases, she said, urging ministers to learn lessons.
Transport Secretary Patrick McLoughlin said that he intended to bring forward the consultation on phase two to begin this year, not 2014, and has asked officials to see whether the entire project can be speeded up.
The route is due to be finalised by the end of next year.
"As with previous consultations, we will work closely with communities and interested parties to find the right balance between delivering the essential infrastructure that we need and respecting the rights and justifiable concerns of those who will be most affected by HS2's construction," he said.
The proposed routes were "a great starting point for the process of engagement to follow", he said, saying it would "deliver a priceless dividend" for the UK.
"While doing nothing would be the easy choice it would also be the irresponsible choice.
Officials said there would be "a generous compensation package for people living near the line" as well as noise and other nuisance mitigation measures such as tunnels.
Cameron said: "Linking communities and businesses across the country and shrinking the distances between our greatest cities, High Speed Rail is an engine for growth that will help to drive regional regeneration and invigorate our regional economies.
"It is vital that we get on board the high-speed revolution.
"We are in a global race and this government's decision to make High Speed Rail a reality is another example of the action we taking to equip Britain to compete and thrive in that race.
"High Speed Rail is a catalyst that will help to secure economic prosperity across Britain, rebalance our economy and support tens of thousands of jobs."