Theres two flaws in the Public Accounts committees report, firstly it uses the original Government projection of HS1 passenger demand when the project was first mooted, not the Dft model that was used to get approval which had much lower predictions.
Secondly it calculates all subsidy for services on the line as a capital 'loss' (it should be a revenue loss) and then adds it up for future years all the way upto 2070 as a loss today! Thats like saying, 'oh you bought a new tv? you now owe me £8439 for your license fee upto 2070.'
I don't see anything that says that.
EDIT: I found the numbers you were referring to. See below ; more importantly though, is whichever said of figures you use...:
1: Is it paying for itself, or not?
2: Are the passenger numbers as predicted, or not?
They failed to take account of competition and badly misjudged working / travel patterns with HS1.
With HS2, they're assuming that people will commute MORE and use technology LESS in 20 years time and be flying less between two locations which aren't connected by air anyway.
Remember, this disaster of a plan for HS2 was put together by the same government that explained that a
maximum of 13,000 migrant workers would come to the UK, that the Olympics would cost £2bn, that the Millennium dome would be a success and that light touch city regulation would assist in their policy of being "intensely relaxed about people becoming filthy rich".
If you can't hear alarm bells ringing, I think a hearing test and lessons in economics, politics and history are in order...
EDITED TO ADD:
Channel Tunnel rail link leaves £4.8bn debt
International passenger numbers on HS1 are only a third of the 1995 original forecast and two-thirds of the level the Department for Transport (DfT) forecast in 1998, said the committee.
It went on: "Over-optimistic and unrealised forecasts for passenger demand on HS1 left the taxpayer saddled with £4.8 billion of debt."
The report added that the delivery of regeneration benefits from HS1, on which high-speed Eurostar trains travel, "suffered from a lack of effective leadership from the centre".
The committee said the department "does not have sufficient understanding of the economic impact and regeneration benefits of transport infrastructure, compared with alternatives, so is not able to make fully informed investment decisions".
The report added that the DfT "gives insufficient attention to evaluating its major projects" and should develop evaluation frameworks for all current major projects including the under-construction cross-London Crossrail scheme and HS2.
Ms Hodge said some of the DfT's assumptions about the benefits of faster travel were "simply untenable".
"For example, the time business travellers save by using high-speed rail is valued at £54 per hour yet the time commuters save getting to and from work is only valued at £7 per hour.
"It is difficult to see how this can be justified. The department also assumes that all time spent on a train is unproductive. And unrealistic assumptions about ticket prices act to exaggerate passenger demand forecasts."