10/01/2012 04:43 GMT | Updated 10/03/2012 05:12 GMT

HS2 Approved By Transport Secretary Justine Greening, But Campaigners Likely To Appeal Decision In The Courts

The government has approved the HS2 High Speed rail line project from London to Birmingham, in a project which will cost £17 billion in its first phase and take nearly 15 years to complete.

The high speed line would connect England's two largest cities and reduce journey times to just under 50 minutes, but many campaigners question whether the line will reduce overcrowding on the existing West Coast Main Line, which is often subject to delays and standing-room only during rush hour.

The plans were significantly revised to include more tunnels along the route. Areas of natural beauty such as the Chiltern Hills are expected to see more tunnels to alleviate objections from campaigners.

Transport secretary Justine Greening said the decision had to take in both the "environmental impact" and "benefits" of HS2: "I could have made the easy choice", she told MPs. "But let's be clear the price for that would have been paid in lost business, lower growth, fewer jobs... Good government is about acting in the longer-term national interest."

Full coverage of the HS2 decision by the government:

A 1.4 mile tunnel in Amersham in Buckinghamshire has been introduced to the plans, which will help avoid a cabinet resignation by the local MP Cheryl Gillan. The Welsh Secretary had said that she would oppose the Bill.

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.

However many Tory MPs can't see the economic benefits of the scheme. Tony Baldry, whose North Oxfordshire constituency will be affected by the route, believes the whole thing might not happen at all.

"Let's put it this way. When the M40 extension was agreed in the mid 1950s it took until the 1980s until it was actually built. Until they actually start laying track I don't think there's any certainty it will actually be built. I think that's all the more reason, given the huge sums involved, one needs to be satisfied that one's getting good value for the taxpayer. "

In a sign that those opposed to HS2 will challenge the decision in the courts, the Countryside Alliance criticised the changes made to the plans, which include extending the line to the north of England once the first phase of HS2 is completed.

The Countryside Alliance said: "These last-minute changes, as with the route north of Birmingham, have also not been put forward for public consultation and therefore risk huge public and stakeholder backlash.

“The Alliance calls on the Government to undertake these assessments and consultations as a matter of urgency, before any further progression is made on this project.”

Initially put forward by Labour, HS2 has been strongly supported by the coalition government, the rail industry and big business.

The Government has argued that the scheme, including the second phase Y-shaped extension to Manchester and Leeds, will generate £44 billion of benefits to the economy over 60 years.

Labour have agreed to the plans so they will almost certainly be passed by the Commons.

The HS2 route will start at a rebuilt Euston station in London and would run, in the first phase, as far as a new Birmingham city centre station at Curzon Street.

A second interchange station would be constructed where the line of the route passes the National Exhibition Centre (NEC) and Birmingham airport close to junction six of the M42.

It would offer direct links to Birmingham airport, the NEC, the M6 and M42.

But residents in the Chilterns as well as some local authorities and Tory MPs have been vehement in their opposition to the project which will see the first phase completed by around 2026, with the extension north of Birmingham completed by around 2032/33.

The creation of HS2 will mean some homes will be demolished and some households suffer from noise.

Those against the scheme have stressed that the UK would be better off enhancing the existing rail network, particularly the London to Scotland West Coast Main Line (WCML).

But in a government-commissioned report, Network Rail said that improving existing rail lines would not solve the problem of overcrowding.

The long run-up to this morning's announcement has been studded with reports from various organisations pointing out the various pros and cons of the scheme.

While government, train companies and some businesses have produced figures to support HS2, opponents have announced their own statistics pointing to the whole scheme being a waste of money.