Is there any provision at present for a certain percentage of the new slots to be assigned to domestic routes? A Telegraph article suggests that while a member of the EU this would not be possible (but I'm not sure that this is true - BE has 'domestic only' slots, albeit a temporary restriction). Currently 6% of LHR flights are domestic. If central Government are serious about "Global Britain" and "Northern Powerhouses" and making sure that additional runway capacity in the SE benefits all of the UK then restrictions on slot use seems a reasonable idea. Heathrow could, themselves, encourage domestic operations and reduce handling charges for aircraft of <100 seats, or Turboprops.