The government will next week announce its decision on whether to favour expanding either Heathrow or Gatwick airport, after decades of delays.
Unusually, the decision will not be taken by the full cabinet but by a sub-committee, chaired by Theresa May.
MPs will not get to vote on the decision for at least another year.
Some ministers will be allowed to speak out against it for a limited period in a move being seen as evidence a third runway at Heathrow will be backed.
Expanding Heathrow is strongly opposed by Foreign Secretary Boris Johnson, and Education Secretary Justine Greening.
Allowing ministers to speak out could avert the possibility of resignations from cabinet.
In a letter, Prime Minister Theresa May has told cabinet colleagues that once a decision has been taken by the airports sub-committee on the preferred scheme it will then be subject to a "full and fair public consultation" before a final decision is put before the Commons in the winter of 2017-18.
Number 10 would not comment as to whether MPs would be able to vote freely on the matter.
A Heathrow spokesperson said it was "the expected and appropriate political process" - a view echoed also by Gatwick.
CILT's policy on this issue is that the Heathrow North West Runway option is preferable, primarily based on transport and logistics considerations. To read CILT's submissions to the Airports Commission, visit: /publicpolicy
Source: BBC News