The approval of the £32 billion HS2 high-speed rail project has received a mixed reaction from industry bodies and associations.
The Taxpayers' Alliance and the Stop HS2 campaign both said the project was "a white elephant", while the Institute of Economic Affairs said the scheme was "economically flawed".
Jerry Marshall, chairman of Agahst (Action Groups Against High Speed Two), said HS2 was "a disaster waiting to happen", but the British Chamber of Commerce said rail services would get worse without the new line and the CBI said the announcement was welcome.
Stop HS2's campaign co-ordinator, Joe Rukin, claimed the route was simply the "wrong priority" for the country. Mr Rukin, from Kenilworth in Warwickshire, said: "There is no business case, no environmental case and there is no money to pay for it."
However in an attempt to appease opponents of the controversial scheme, including some Tory MPs, Transport Secretary Justine Greening has announced extra tunneling for sections of the 140-mile route between London and Birmingham.
“A new high speed rail network will provide Britain with the additional train seats, connections and speed to stay ahead of the congestion challenge and help create jobs, growth and prosperity for the entire country,” said Ms Greening.
The link between the UK's two biggest cities, which passes through picturesque Tory heartlands, will form phase one of the scheme, with a hybrid bill being introduced in Parliament next year.
Welsh Secretary Cheryl Gillan, whose constituency is Chesham and Amersham, has threatened to resign over HS2.
Labour is expected to support the HS2 plans, but it remains to be seen whether the latest changes will be enough to satisfy Ms Gillan and other Tory "rebels".
HS2 has attracted the anger of local residents and councils, as well as conservationists and other industry bodies.
The Institution of Engineering and Technology (IET) says the HS2 rail plans are "fundamentally flawed".
The first £16.4 billion phase, introducing 225mph trains and cutting London-Birmingham journey times to 49 minutes, would be completed in 2026.
This first phase will also include a connection to Europe via the Channel Tunnel, and on completion of HS2 the network will include a direct link to Heathrow Airport.
A second phase, taking HS2 to Manchester and Leeds in a Y-shaped route, would be completed around 2032/33.
A formal consultation on second phase routes will begin in early 2014 with a final route chosen by the end of 2014.
New measures announced by Ms Greening include a 1.4-mile tunnel near Amersham in Buckinghamshire.
There will also be a new 2.75-mile tunnel in Ruislip in north-west London.
Other new tunnels, or extensions to already-planned tunnels, will be at Greatworth in Northamptonshire, Turweston in Buckinghamshire, Chipping Warden and Aston le Walls in Northamptonshire, Wendover in Buckinghamshire, and Long Itchington Wood in Warwickshire.
Many rail associations have voiced their support of the HS2 project.
“We welcome and fully support the go ahead for HS2, a project that will radically transform the UK rail network”, said RIA Director General Jeremy Candfield.
The government says the scheme will produce economic benefits of £47 billion over 60 years, and that improving existing infrastructure will not be enough to cope with overcrowding on an increasingly-busy rail network.
“HS2 will not only transform travel between our major cities, it also represents the best solution for solving the looming capacity crunch on the West Coast Main Line," said Paul Plummer, Network Rail group strategy director.
Michael Roberts, Chief Executive of the Association of Train Operating Companies (ATOC), said: “HS2 would help to alleviate the capacity crunch on many of our major rail corridors and offer the prospect of shorter journey times between London and other major English cities.
“It would also allow for faster and more frequent local services in areas between London and Birmingham, as space is freed up on existing lines.”