Britain's high-speed rail infrastructure project was given the go-ahead by the prime minister in February 2020 but ambitions for the extent of the scheme have since been curtailed .
What is HS2?
HS2 is a planned high-speed rail network initially set to link London and the West Midlands, with a further phase extending to Manchester and the East Midlands.
Britain's biggest infrastructure project has had support from governments of all stripes since it was first mooted more than a decade ago but it could be the 2040s before passenger services are operating on the full network.
HS2's inception follows the development of HS1, the high-speed line between London and Kent connecting the UK to routes on the European continent.
The aim is to run 18 trains an hour in each direction to and from London - at speeds of up to 224mph.
It involves the construction of more than 300 bridges and 70 viaducts for the London-West Midlands phase alone.
More on Hs2
- HS2: 10-mile long tunnel under Chiltern Hills completed almost three years after setting off
- North and Midlands to share £4.7bn local transport fund after HS2 rail leg scrapped
- West Midlands and Greater Manchester mayors outline options to revive rail after axing of northern leg of HS2
Related Topics:
- HS2
The project is designed to meet the long-term growth in demand for rail services, improve the reliability of the network, boost connectivity by making journeys faster and easier, and help economic growth across the UK.
What is the route?
Stations on the first phase of the line will be London Euston, Old Oak Common in west London, Birmingham Interchange and Birmingham Curzon Street.
The second phase will see trains head northwest to Manchester Airport and Manchester Piccadilly via Crewe.
They had also been planned to go northeast from Birmingham towards an East Midlands hub at Toton from where they would continue on the HS2 line to Leeds.
But the Leeds section has now been scrapped and the Toton plan abandoned, meaning the high-speed line will instead stop at the existing East Midlands Parkway station, with trains then running into Nottingham and Derby.
It is estimated that when these sections are complete, a journey from London to Manchester will take one hour and 11 minutes, while London to Nottingham will be 57 minutes.
Where did it all begin?
In 2009, under Labour transport secretary Geoff Hoon, the government set up a company, HS2 Ltd, to look at proposals for a new high-speed line.
The following year, the Department for Transport (DfT) set out plans for a Y-shaped network connecting London and the cities in the North.
Later under the Conservative-Liberal Democrat coalition, it was confirmed that the line would be built in two phases.
Phase 1 would run from London to the West Midlands, beginning in 2026.
Phase 2, extending from the West Midlands to cities in the North, would start in 2032-33.
What's the hold up?
By July 2019, the government accepted that timetable was no longer feasible and the expected completion dates were pushed back.
Reasons for the delay include a year spent revising cost and schedule estimates for Phase 1 and more time being needed for construction at various sites.
In August 2019, the government announced an independent review of the programme to advise on whether to proceed.
Meanwhile, the government's Infrastructure Projects Authority (IPA) has flagged serious concerns about the project.
In its 2020-21 annual report, the IPA gave Phase 2b of the scheme - comprising extensions to the north - a red rating meaning successful delivery "appears to be unachievable".
Phase 1 has an amber/red rating meaning delivery is "in doubt, with major risks or issues apparent in a number of key areas".
Phase 2a - the section from the West Midlands to Crewe - has an amber rating meaning it is "feasible" but that "significant issues already exist requiring management attention".
What has changed since 2020?
The Leeds extension fell victim to the government's integrated rail plan (IRP), which reconsidered the earlier plans partly because of rising costs.
It decided instead to upgrade existing lines serving the region as part of a wider £96bn strategy focused on the Midlands and the North.
Grant Shapps, the transport secretary, said it would mean passengers seeing real improvements a decade earlier than they would have expected.
Phase 1 of HS2 remains pencilled in for completion between 2029 and 2033 and Phase 2a to Crewe "by around 2035".
But the completion of high-speed links to Manchester and the East Midlands are bracketed as something customers "could see" by the early to mid 2040s - having previously been estimated at 2036-40.
How much is it going to cost?
At the time of the 2010 election, estimates of the cost of HS2 ranged upwards of £20bn.
By January 2012, when the broad route of the proposed scheme was in place, this had risen to £32.6bn.
In June 2013, the coalition government increased the overall cost to £42.6bn and in November 2015, when the figures were updated, in line with inflation, to £55.7bn.
In early 2021, the DfT's latest estimate of the cost of HS2 has spiralled even higher stood and early in 2021 stood at between £72bn and £98bn.
Lord Berkeley, former deputy chairman of the government's independent review into the project, had said it could climb to £107bn.
The curtailment of HS2's eastern leg looks likely to curb costs but to what extent remains unclear from figures published in the IRP.
They showed that costs for the first phase and western extension of the project, added to money already spent, were now estimated to total just under £68bn, with an unspecified part of £12.8bn in "eastern core network" spend also going on HS2.
That appeared to suggest a total of around £70bn.
What are the arguments for and against?
Governments have insisted that HS2 - whose cost will largely be borne by the taxpayer - is a good investment for the country.
They say it will deliver growth, particularly in the English regions, and have a positive impact on jobs.
Those opposed to it dispute those claims, saying that the money would be better spent on improving rail capacity elsewhere, and that it will blight homes and damage the environment where the route is to be built.
Why have the costs risen so much?
A report in January 2020 by the National Audit Office (NAO) - the spending watchdog - said HS2 Ltd had not accounted for the level of uncertainty and risk in the plans.
It used a method for calculating how much extra might be needed "that was not appropriate for a programme at such an early stage of development".
Among the factors causing higher costs were commitments to increase the length of tunnelling and to erect noise barriers.
The NAO said the government and HS2 Ltd had "not adequately managed risks to taxpayer money".
More money was needed for building bridges, tunnels and stations than first thought.
Complex issues involving the discovery of asbestos and archaeological remains, and the need to divert more gas and power lines than expected, have caused problems too.
Extra cash was also needed to buy up properties to make way for the rail line.
Even after these have been accounted for, there is further uncertainty about the cost of extending London's Euston station to accommodate high speed trains.
What has actually been done so far?
Construction began in September 2020.
The government said in October 2021 that work was "well under way" at 340 sites between London and the West Midlands
As of that time, £15.5bn had been spent on the project.
