I found the CAA consultation
CAP1914 "
Economic regulation of Heathrow: programme update" interesting as a step forward in formalising the situation.
"
This document provides an update on our programme for the development of the economic regulation of Heathrow Airport Limited (“HAL”) in the light of the very significant uncertainties brought about by:
> the severe impact of the Covid-19 pandemic on the aviation sector as a whole and passenger numbers at Heathrow airport;
> the Court of Appeal’s decision setting aside the Airports National Policy Statement; and
> HAL’s subsequent decision to pause its programme for expanding Heathrow airport.
It outlines our proposals for changing our overall approach to developing the regulatory regime for HAL in the light of these developments."
There is a clear focus on a 2 runway Heathrow .
CAP1914: Economic regulation of Heathrow: programme update