Video report by ITV News Consumer Editor Chris Choi
Boris Johnson has thrown his weight behind controversial HS2 plans that could shuttle passengers from London to Birmingham in 45 minutes on 225mph trains.
Mr Johnson said in the House of Commons on Tuesday "this country is being held back by its infrastructure" as he approved Phase 1 between London and Birmingham.
The next phase would connect to Manchester and Leeds.
The project’s initial budget was £32.7 billion at 2011 prices but a leaked review by Douglas Oakervee last year found it could cost up to £106 billion.
Despite "poor management", the prime minister said he believes in the "fundamental value" of HS2.
He told MPs: "When it comes to advocating HS2, it must be said that the task is not made easier by HS2 Ltd, the company concerned.
"Speaking as an MP whose constituency is on the route, I cannot say that HS2 Ltd has distinguished itself in the handling of local communities."
He added: "But poor management to date has not detracted, in my view, from the fundamental value of the project."
He defended his decision to continue the project, saying "everybody always tries to stop big infrastructure projects at round about this moment".
"The Treasury, if they had got their way, would have stopped the M25. The Treasury would never have allowed the Channel Tunnel to go ahead.
"HS2 actually has a better business case today than the M25 had."
He added: "I remember when I was mayor of London... they tried to stop Crossrail."
Mr Johnson also confirmed intentions to run further than Birmingham and to Manchester in Leeds in what would be Phase 2.
He said: "This is not just about getting from London to Birmingham and back.
"This is about finally making a rapid connection from the West Midlands to the Northern Powerhouse, to Liverpool, to Manchester, to Leeds and simultaneously permitting us to go forward with Northern Powerhouse Rail across the Pennines - finally giving the home of the railways the fast connections they need.
"And none of that, none of it makes any sense without HS2."
To oversee the project, Mr Johnson said he will appoint a minister along with a ministerial oversight group that will be "tasked with making strategic decisions about it".
High-speed trains would also run beyond the new lines on existing tracks as far as Edinburgh and Glasgow.
Trains serving Newcastle and Edinburgh could stretch to 400 metres - the length of nearly four football pitches.
HS2 Ltd - the Government-owned company responsible for developing and building the railway - says it will boost capacity and cut journey times.
Mr Johnson's announcement came as the Government pledged a £5 billion cash injection to overhaul bus and cycle links in English regions outside London.
Why are there concerns over the project?
Former HS2 Ltd chairman Douglas Oakervee was commissioned by the Government in August 2019 to lead a review into whether or not the programme should be scrapped amid rising costs and delays.
It has been widely leaked that the review found HS2's cost could hit £106 billion - but concluded that "on balance" it should continue.
Mr Johnson also said in the Commons: "The review recently conducted by Douglas Oakervee ... leaves no doubt of the clinching case for high-speed rail.
"A vast increase in capacity with hundreds of thousands of extra seats making it much easier for travellers to move up and down our long, narrow country.
"And that means faster journey times, not just more capacity."
It was due to open in December 2026, but HS2 Ltd chairman Allan Cook said last year it would be "prudent to plan for an opening between 2028 and 2031".
Jeremy Corbyn says he fears 'nothing has changed'
Last month, Whitehall's spending watchdog said the scheme is over budget and behind schedule because its complexity and risks were under-estimated.
The National Audit Office warned that it is impossible to "estimate with certainty" what the final cost could be.
The Wildlife Trust has a longstanding opposition to the project, which it says will cause a "vast scale of destruction" to nature.
Nikki Williams, the trust's director of campaigns and policy, said in response to Mr Johnson's speech: “Nature is paying too high a price for HS2."
He added: “It is vital that HS2 does not devastate or destroy irreplaceable meadows, ancient woodlands and internationally important wetlands that are home to a huge range of wildlife, from barn owls to butterflies.
"Green and sustainable transport is vital, but the climate emergency will not be solved by making the nature crisis worse."
ITV News Reporter Stacey Foster speaks to residents in Kenilworth: