The disclosure comes as new documents, published by HS2 on its website, suggest that the hardship caused by the scheme will in many areas be greater than expected, and the benefits less.
The documents include "sound contour maps” showing that, along much of the route, thousands more people than predicted will suffer noise from the new high-speed trains. The new maps show that a thousand homes near a one-mile stretch of the line at Aylesbury alone, for instance, will be affected by "potentially significant” noise from the line. About 2,400 people live in these properties.
The noise-blighted areas in Aylesbury and many other places are bigger than on a previous noise map issued in February 2011. In London, however, longer tunnels will reduce the noise footprint.
The documents, draft "environmental statements” for HS2, were slipped out the same day last week as a damning National Audit Office report into the project, and have so far gone almost unnoticed.
The documents also say that HS2’s first phase, from London to Birmingham, will demolish factories and businesses employing 11,000 people, 7,600 of them directly working on the premises and a further 3,350 in supply chains.
The HS2 documents claim that 80 per cent of these jobs will relocate, but admit that almost 2,200 existing jobs could be lost. However, the documents insist that "a large proportion of any employees who lose their jobs would be able to re-enter the workforce relatively quickly given the size and strength of the relevant local labour market”.
The documents show that the London district of Camden Town, home to one of the capital’s most popular tourist markets, will be turned into a building site for eight years as seven Victorian railway bridges through the centre are ripped out and replaced with modern bridges to carry a link between HS2 and the Eurostar line.
London’s £1.5 billion Overground rail service, the line with Britain’s highest punctuality and customer satisfaction, uses many of the bridges and will be disrupted, potentially for years, during the work.
Traffic across north London will also be disrupted as major roads are closed during the bridge replacements. The documents do not mention key environmental aspects of the scheme, such as its likely carbon footprint. Details of this will be provided later, they say.
Ministers have admitted that HS2, which will use large amounts of electricity, will fail to reduce CO2 emissions and may well increase them. Earlier assessments show HS2 will do little or nothing to cut road and air travel.
The documents also gloss over the effect of losing community facilities, such as pubs, restaurants and a public park due to be built over in the Euston area of London, saying there is "unlikely” to be any long-term impact because "the community is expected to adjust, and new or replacement facilities would be developed if demand exists”.
The new details emerged as the National Audit Office, the spending watchdog, said the benefits of HS2 were "unclear”, the business case was flawed and there was no evidence for ministers’ job-creation claims.
The NAO report reveals new evidence showing ministers and civil servants made misleading statements in support of the scheme. In September last year Philip Rutnam, permanent secretary at the Department for Transport, told MPs on the transport select committee that the Government’s most recent estimate of the benefits from HS2, issued the month before, was based on "the most up-to-date information that we had”.
In a letter at the time to the HS2 Action Alliance, an anti-HS2 group, Mr Burns repeated the claim that the estimate of benefits was based on "the best information that we had available at the time”.
The NAO report makes clear that by August 2012 the DfT knew that its forecasts for rail passenger growth "a key part of its justification for the new line — were grossly exaggerated”. In that month, the department had officially adopted a new method of predicting passenger demand which would have produced a much lower growth forecast and thus an even less convincing business case for HS2.
The method was initiated in the department as early as 2009 and had already been used by the DfT to assess another major rail scheme, the West Coast main line. But the department decided not to use it on the HS2 project.
Other estimated benefits of the scheme, the NAO found, were based on assumptions almost 10 years out of date, including the key assumption — a cornerstone of HS2’s business case — that all travelling time is unproductive and that shorter journeys will thus increase productivity.
Three years before, research for the DfT itself said that the rise of laptops and mobile telephones made this assumption untenable. The researchers also found that most travellers would do no extra work in the time they saved.
Hilary Wharf, chairman of the HS2 Action Alliance, said: "It is a telling sign of HS2’s weakness that the Department for Transport have felt it necessary to distort the business case, and to mislead Parliament about it. The problem with HS2 is that it cannot be justified without bending the truth.”
A spokesman for the Department for Transport said: "It is entirely incorrect to suggest that Simon Burns or the Permanent Secretary have misled Parliament or anyone else. In August 2012 the DfT changed the process for developing detailed economic modelling for large transport infrastructure projects and it would have been wrong to make sudden changes at a very late stage to detailed work already under way on the HS2 economic case."