The Government has signalled the go-ahead for the £32 billion HS2 high-speed rail project that will drastically reduce journey times between major UK cities.
In an attempt to appease opponents of the controversial scheme, including some Tory MPs, Transport Secretary Justine Greening announced extra tunnelling for sections of the 140-mile route between London and Birmingham.
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.
This first £16.4 billion phase, introducing 225mph trains and cutting London-Birmingham journey times to 49 minutes, would be completed in 2026. A second phase, taking HS2 to Manchester and Leeds in a Y-shaped route, would be completed around 2032/33.
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.
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".
Passing through beauty spots, HS2 has attracted the anger of local residents and councils, as well as conservationists.
But the Government reckons the scheme will produce economic benefits of £47 billion over 60 years. It also says that improving existing infrastructure will not be enough to cope with overcrowding on an increasingly-busy rail network.
Ms Greening said: "The faster journeys on HS2 - Edinburgh and Glasgow will be just 3.5 hours from London - could transfer around 4.5 million journeys per year who might otherwise have travelled by air and nine million from the roads."