Campaigners have lost their latest legal battle over the government's £50 billion HS2 project.
The line would provide a high-speed link between London and Birmingham in its first phase, with later stages extending to the north of England.
Protesters accused the government of unlawfully failing to carry out a strategic environmental assessment, which they say could help tackle costly problems for people living along the proposed route.
But three appeal judges today unanimously rejected the challenge.
Train journey times between northern English cities could be slashed by half after ministers backed plans for a third high-speed railway.
The proposals were put forward in a report from the head of the £50 billion HS2 high-speed rail project, Sir David Higgins.
The improvements would cover an east-west section of northern England and would be in addition to the north-of-Birmingham phase two of HS2 which will see a Y-shaped route going to Manchester and Leeds.
Sir David said northern connectivity plans - dubbed "HS3" and backed by Chancellor George Osborne - would be "as important to the north of England as Crossrail is for London".
If carried forward, the plans would mean journey times between Leeds and Manchester could almost be cut in half.
While journeys between Leeds and Birmingham, Leeds and Sheffield Meadowhall, York and Birmingham and Nottingham to Birmingham could also be reduced by a half or more, and many more journeys across the country substantially shortened.
"Improving connectivity is vital if Britain is to compete in the knowledge economy in which this country has a competitive advantage, but in which ease of travel is an essential element."
A huge redevelopment around the HS2 project, creating 14,000 jobs, 2,000 homes and worth up to £1.3 billion a year to the economy, is being announced by the Government today.
Transport Secretary Patrick McLoughlin is launching a regeneration body that will drive economic growth around the Curzon Street HS2 city centre terminus in Birmingham.
He is also announcing the location of the high-speed rail project's construction HQ, which taken together sees the creation of a large number of jobs, significant regeneration of the city centre and a massive economic boost to the city.
HS2 is a vital part of our long-term economic plan. By locating the new HS2 engineering HQ in Birmingham we are bringing skilled job opportunities into the area, spreading HS2's benefits beyond those using the new rail line.
Tonight's vote in Parliament on the HS2 bill means the high-speed rail line will begin construction in 2017, the Transport Secretary has confirmed.
Patrick McLoughlin also tried to calm the fears of anti-HS2 campaigners over the impact of the proposed route on their areas, saying:
"I am aware of the concerns some who live very close to the HS2 route have. I am confident however that by working together we can ensure this vital new north-south railway is designed in the right way, and we will have spades in the ground in 2017 as planned."
ITV News Deputy Political Editor Chris Ship has been following the votes on the HS2 bill in the House of Commons.
MPs have now voted in favour of giving the legislation a second reading.
Campaigners who object to plans for a new high speed rail link on environmental grounds are talking "b*******" and only really care about their house prices, according to Mayor of London Boris Johnson.
Johnson claims that protesters "pretend" they are campaigning about woodland or wildlife but they are much more "furious" about the impact HS2 proposals are having on property values.
He suggested the Government should buy up the houses of the scheme's opponents for "top dollar", then when the rail link is finished, capitalise on any boost to local economies by selling them off for a profit.
Mr Johnson told Total Politics magazine: "People are in the humiliating position of having to pretend that there's some environmental objection that they have, that the great crested grebe is going to be invaded or whatever."
"What they care about is their house prices. It's tragic we have protest groups talking about 'this ancient woodland' when actually there's no tree in this country that's more than 200 years old.
"It's b*******. They're not campaigning for forests, they're not campaigning for butterflies. They pretend to be obviously, but what they're really furious about is that their house prices are getting it."
Around 500 wildlife areas could be at risk from the HS2 high speed rail line, conservationists have warned.
The Wildlife Trusts called for a £130m investment to create new green areas over the length of the new line.
Among the areas affected by the new line are 43 ancient woods and nine Wilflife Trust nature reserves.
Tory MP Michael Fabricant has been sacked as vice-chair of the party after criticising the HS2 rail scheme and Maria Miller over her expenses.
The former Conservative whip claimed on Twitter that he refused to resign so was sacked by party chairman Grant Shapps.
After news of Mrs Miller's resignation broke, the MP said: "Well, about time."
Mr Fabricant, MP for Lichfield in Staffordshire, tweeted this announcement:
Been asked to resign as Vice Chairman, refused, so sacked over HS2 and my views on a recent Cabinet Minister. Still available 4 speeches etc
After Mrs Miller resigned over her expenses scandal, he tweeted:
Note to self: If ever a minister again, be like Mark Harper. If in trouble, resign quickly & in a dignified manner. Lesson to us all.
He is set to lead a Tory revolt against the £50 billion HS2 scheme later this month by calling for laws so the London-Birmingham is denied a second reading in Parliament.
The MP has spoken of his shock at being sacked and wrote on Twitter:
The head of HS2 has said construction of the high-speed rail line should be speeded up, with a new hub in Crewe six years earlier than initially planned.
ITV News Deputy Political Editor Chris Ship reports.