Old,notbold you say
At the risk of repetition, the Police do not have the powers to detain people aboard an aircraft against their will, regardless of its position, its doors' position and/or its park brake's position.
- but I did not say what you think I said. I responded only to the issue of the legal position of the commander.
If you read my previous posts you will see that you and I are cut from the same cloth on this business. However, while I take your point, I am somewhat more cautious than you. When the captain's authority is clear, then he or she can use it appropriately. However, what the police said was - in law - correct. And that FACT should give any captain, no matter how sure he is of himself, serious pause for thought (not least because he might be subsequently judged to have acted or interfered where he had no right to interfere - and possibly to the detriment of those involved).
Furthermore, if the police believe there is a security situation on the ground - when the captain has no formal authority - and determine a suitable course of action then it would be a courageous captain who decided to disagree (unless he had evidence of a "clear and present danger"). I see that case - where the responsibility for what takes place is clearly with the police - as being distinct from a case where the captain is responsible, but has no authority or willingness to act.
By the way, it could be considered fanciful to suggest that the police in such circumstances "do not have the powers to detain people" .. I think I would prefer that you argued that in court than I!
That being said, I agree with the thrust of your observation that:
Most people on this thread have got it right; don't ask permission, you don't need it.