To ask the Secretary of State for Transport, what investigations into extending the HS2 Chiltern Tunnels are ongoing; and when a final decision will be made on any such extension.
The House of Commons Select Committee considered the possibility of a bored tunnel passing through the whole of the Chilterns AONB, continuing north of Wendover, in great detail. The proposal was rejected, primarily on the grounds of cost.
Since Royal Assent for the Phase One Act in February 2017, HS2 Ltd have been proceeding on the basis of the tunnel design as set out in the Act. There are no investigations into extending the tunnel and no plans to do so.