The Wendover Mined Tunnel was considered in detail during the passage of the Phase One Bill in both the Commons and Lords committees. Cost comparisons of the consented scheme and the tunnelled alternatives were considered in evidence to both committees during the Bill process and the primary conclusion was that the now consented scheme would be less expensive than the tunnelled alternatives.
Since then, DfT officials and HS2 Ltd have been challenged by Wendover Parish Council and your predecessor, Sir David Lidington, over these decisions and have presented further reports by OTB and Michael Byng (mbpc) challenging the consented scheme.
In each instance, it has been concluded that the Wendover Mined Tunnel would be harder to construct, is costlier and involves a significantly greater degree of risk to the consented scheme.
The Department and HS2 Ltd remain convinced that the Select Committee made the right decision when they accepted that there was a significant difference in cost between the mined alternative schemes and concluded that the HS2 Ltd scheme should be retained.
Even if the alternative mined schemes were broadly comparable in these respects, the subsequent costs of seeking legislative consent for the detailed design change and the consequential cost of delaying the introduction of HS2 services do not represent good value for money or an effective use of public money.