But the draft report, seen by the Financial Times, now predicts the cost has increased and equates to £1,600 for each person in Britain.
While recommending that the southern part of the line still goes ahead, the report urges a six-month “pause” before the second phase is implemented to evaluate whether using existing tracks could be more cost-efficient than building a totally new line.
Proponents bill HS2 as a much-needed infrastructure update and a necessary step for the future, but critics say the eye-watering costs could be used more efficiently to update existing links across the country.
Upgrading existing track and scrapping HS2 would cause "absurd disruption" for passengers, according to the chief of Network Rail.
Regardless of where you stand on the issue, here are some other ways the the government could spend £106bn.
Fund the NHS for a year
The Department of Health spent £115bn on the NHS England budget in 2018-19, according to Full Fact. Meanwhile, you could pay for up to eight years of healthcare in Scotland, which is estimated to have cost Holyrood £13.1bn in the same year.
Alternatively you could pay for 2.75 million nurses on a salary of £38,500 – no doubt helping to alleviate the shortage of tens of thousands predicted by 2021.
With Britain’s population ageing, and joint replacements rising, the money for HS2 could also fund nearly 11 million hip replacements.
Build 200 large hospitals, or 1,000 small hospitals
Matt Hancock’s pre-election pledge to build 40 new hospitals came under fire as it was quickly revealed that funding was in place for just six – including extensions to existing healthcare centres.
The £106bn likely required for HS2 could be used to build 195 new large hospitals, judging by the recent cost of £545m to build Queen Elizabeth Hospital in Birmingham, which opened in 2010.
The budget for revamping or building smaller hospitals has been reported to be as small as £100m by Full Fact, which translates to 1,000 new hospitals in exchange for HS2.
Pay for nearly four million university courses
With student fees for UK residents capped at £9,250 per year, the money would be enough to pay for three years of university tuition for 3,819,000 people. It could also fund three years of the most expensive nursing bursaries available for more than a million people.
Pay for a year's-worth of pensions
The UK spent £92bn on state pensions in 2016-17, according to the Office for Budget Responsibility, and is the UK’s largest single expenditure.
Numerous large-scale rail projects
A common argument against HS2 is that there could be more efficient ways of ensuring the country is better connected.
For example, the Great North Rail Project – which will stretch across Yorkshire and Lancashire – is estimated to cost £13bn and is expected to be completed in 2022, contrasting with HS2’s proposed completion date of 2032.
Fund the royal family for a millenium
The Sovereign Grant – the amount given to the royal family from the public purse – totalled £82.2m in 2018-19. This was significantly more than in previous years due to the costs of refurbishing Buckingham Palace, but even at this higher rate, the money could pay for the grant more than 1,200 times over.
Fund the BBC for 20 years
With Boris Johnson hinting he could scrap the licence fee, there has been increased discussion of the cost of the public service broadcaster. Going by its projected 2019-20 income of £3.9bn, building HS2 could be the equivalent of another 27 years of funding for the BBC.
Run the UK's nuclear arsenal for several decades
While the annual cost of running the Trident missile system and associated submarines is thought to be about £2bn, parliament voted to renew it in 2016 at an estimated cost of £41bn. The Ministry of defence has suggested that scrapping Trident would cost around £4bn over several years.
Half of Brexit
The cost of Brexit will have reached £200bn by the end of 2020, Bloomberg analysis suggests, by which time EU law will be about to cease to be in effect, which will happen on 1 January 2021. However, Bloomberg predicts the costs of Brexit will continue to rise each year.
Big Ben Brexit bong bonanzas into the far future
While Mark Francois' dreams of crowdfunding the £500,000 reportedly required to ring the bell have been dashed by a lack of time to prepare, for the alleged cost of HS2 the European Research Group deputy chairman could hypothetically serve up an annual bong for the next 200,000 years.
The cost was said to be around £500,000 because of ongoing renovations, although previous costs during construction work when a bong has been planned further in advance were £14,200 each – on Remembrance Sunday and New Year's Eve – according to a recent parliamentary question.
Nationalise half of the UK's railways, water and energy companies, and the Royal Mail
Labour’s renationalisation plans in the last general election would have cost at least £196bn, the Confederation of British Industry (CBI) claimed. However this sum was greatly disputed by Labour, which criticised it as "scaremongering".
Many experts pointed out that renationalising the railways could be done at no great cost, if the government were to simply wait for rail companies' time-limited ownership to end before bringing them into public possession for free.
Buy every player in the Premier League
Coming in at the most costly squad, Manchester City’s total market value estimated at just over £1bn by Transfermarkt, with Chelsea in second place at £879m.