Speaking at the aviation conference in London today, Mr Johnson's aviation adviser Daniel Moylan said Mr Johnson had not been consulted about the setting up of the commission and had been "profoundly unsettled" by its interim report.
– Daniel Moylan, Mayor's aviation adviser
Heathrow expansion is not any answer at all, for the proven political reason that it is too toxic for any Government to deliver.
To delete the option of a new airport from the process would mean there was only one solution left that satisfied the Commission's remit: a new runway at Heathrow followed by a fourth.
That is not a bargaining position that any Government will accept or a prescription that any Government will deliver.
Speaking to ITV News London, David Cameron said he had "great faith" in the Head of the Airports Commission, Sir Howard Davies. The Prime Minister added that "all options were still on the table", including an airport east of London.
Watch the interview with David Cameron in full on ITV News London at 6pm.
At today's conference Sir Howard Davies said that with the estuary option there was the "simple challenge of distance", with the schemes being some way from central London. He added:
The economic implications are quite serious as well, such as what would be the effect of closing Heathrow and London City airports.
Asked if the door is shut on all other options, Howard Davies replied:
– Howard Davies, Head of the Airports Commission
I would say the door is half closed on Thames estuary plans. Demand will continue to increase before a new runway is built, therefore other airports must grow too.
Politics got us into the problem with current shape of UK airports, but analysis will get us out of it.
- Boris Johnson's aviation adviser Daniel Moylan is also at today's conference
- London's Mayor is bitterly opposed to a new, third runway at Heathrow and favours, instead, a brand-new airport in the Thames Estuary
- The commission excluded any of the estuary plans in its shortlist published last month but have said it would further study an Isle of Grain airport option
The next steps to decide on future UK runway capacity are being outlined this morning. Sir Howard Davies, the head of the Airports Commission has already shortlisted Heathrow and Gatwick Airports as possible sites for a new runway by 2030.
Today Sir Howard will speak about the commission's work towards a definite runway recommendation - to be made in a final report in summer 2015.