Some of its opponents might be suggesting that today after a report from the National Audit Office basically said Government hasn't made a very strong case for it.
But if you read the report (as I have) you'll realise that its heavily nuanced language does not say that the case cannot be made. Rather, it says it needs to be made clearer.
So the NAO is really saying that the case for HS2 is not clear...yet.
Nevertheless, its analysis of the Government's work on HS2 so far has plenty of ammo for opponents.
The cost-benefit analysis is poor because it contained errors, the business case is built partly on data which is in some cases more than 10 years out of date.
Then there's the small matter of an apparent £3bn funding gap in the first phase, and a challenging timetable for that first phase to actually get going.
Civil service insiders will tell you it's a must-do-better warning shot rather than a damning verdict. The money almost certainly can be found and ministers were already revising their case for HS2 when the NAO was drawing up its report.
Neverthless, the NAO's report reads like an analysis of a hard-pressed government department trying to push through an enormously complicated project to a tight timetable when it's short of expertise. The big risk there is that expensive mistakes are made (remember the West Coast franchise fiasco?).
What about Nottingham, which is hoping to benefit from an HS2 station at Toton in stage 2 of this £30bn project? The positive is that the NAO believes the economic benefits of the second stage should be much stronger than the first stage.
But if its warnings about the first stage timetable are proved accurate our long wait for that second stage may be longer still.