Thanks David! 
Out of curiosity, how might would you suggest removing a PO with ‘reasonable force’? 
Get some friends around and start moving their belongings into the street. Give them plenty of notice that you will be evicting them that day. Make sure it doesn’t escalate into violence or you could then be committing a crime. There is a small risk that they could try to sue you under the Interference with Goods Act, but I think its unlikely they would win.
Whilst I love the approach I’m assuming PO would call the Police pretty quickly, who in the absence of a bailiff/court approved warrant would probably make me leave?
Although technically trespassing how can this be proved, PO would probably just say his AST in the house somewhere? …& taking a copy of my Deeds probably not sufficient to complete the possession?
Sorry, so many questions but this is fascinating & really useful stuff!!
You would need to take some evidence with you to convince the Police, such as the relevant section of the Protection from Eviction Act 1977. Police dont usually know much about the law and may still suggest you get a court order. I should be up front here and say that I have no experience of this approach and don’t know of anyone who has tried it. I think its worth a try provided you are willing to back off if things get hairy or the Police try to stop you. At that point the risk of a breach of the peace is too great. In fact I did hear of one landlord who asked the Police to attend in case there was a breach of the peace. That would give you the opportunity to set out your case in advance and get them on side. I’m not sure if they would hell in practice though.
Thank you…Seems a bit of a grey area but I understand what you’re saying.