For those dealing with the bailiff mafia check out this definitive case law that will protect you.
Equity aids the vigilant, not he who sleeps on his rights...
A debtor can remove right of implied access by displaying a notice at the entrance. This was endorsed by Lord Justice Donaldson in the case of Lambert v Roberts  72 Cr App R 223 - and placing such a notice is akin to a closed door but it also prevents a bailiff entering the garden or driveway, Knox v Anderton  Crim LR 115 or R. v Leroy Roberts  EWCA Crim 2753
Debtors can also remove implied right of access to property by telling him to leave: Davis v Lisle  2 KB 434 similarly, McArdle v Wallace  108 Sol Jo 483
A person having been told to leave is now under a duty to withdraw from the property with all due reasonable speed and failure to do so he is not thereafter acting in the execution of his duty and becomes a trespasser with any subsequent levy made being invalid and attracts a liability under a claim for damages, Morris v Beardmore  71 Cr App 256.
Bailiffs cannot force their way into a private dwelling, Grove v Eastern Gas  1 KB 77
Otherwise a door left open is an implied license for a bailiff to enter, Faulkner v Willetts  Crim LR 453 likewise a person standing back to allow the bailiff to walk through but the bailiff must not abuse this license by entering by improper means or by unusual routes, Ancaster v Milling  2 D&R 714 or Rogers v Spence  M&W 571
Ringing a doorbell is not causing a disturbance, Grant v Moser  5 M&G 123 or R. v Bright 4 C&P 387 nor is refusing to leave a property causes a disturbance, Green v Bartram  4 C&P 308 or Jordan v Gibbon  8 LT 391
Permission for a bailiff to enter may be refused provided the words used are not capable of being mistaken for swear words, Bailey v Wilson  Crim LR 618.
If the entry is peaceful but without permission then a request to leave should always be made first. Tullay v Reed  1 C&P 6 or an employee or other person can also request the bailiff to leave, Hall v Davis  2 C&P 33
Excessive force must be avoided, Gregory v Hall  8 TR 299 or Oakes v Wood  2 M&W 791
A debtor can use an equal amount of force to resist a bailiff from gaining entry, Weaver v Bush  8TR, Simpson v Morris  4 Taunt 821, Polkinhorne v Wright  8QB 197. Another occupier of the premises or an employee may also take these steps: Hall v Davis  2 C&P 33.
Also wrongful would be an attempt at forcible entry despite resistance, Ingle v Bell  1 M&W 516
Bailiffs cannot apply force to a door to gain entry, and if he does so he is not in the execution of his duty, Broughton v Wilkerson  44 JP 781
A Bailiff may not encourage a third party to allow the bailiff access to a property (ie workmen inside a house), access by this means renders the entry unlawful, Nash v Lucas  2 QB 590
The debtor's home and all buildings within the boundary of the premises are protected against forced entry, Munroe & Munroe v Woodspring District Council  Weston-Super-Mare County Court
Contrast: A bailiff may climb over a wall or a fence or walk across a garden or yard provided that no damage occurs, Long v Clarke & another  1 QB 119
It is not contempt to assault a bailiff trying to climb over a locked gate after being refused entry, Lewis v Owen  The Times November 6 p.36b (QBD)
If a bailiff enters by force he is there unlawfully and you can treat him as a trespasser. Curlewis v Laurie  or Vaughan v McKenzie  1 QB 557
A debtor cannot be sued if a person enters a property uninvited and injures himself because he had no legal right to enter, Great Central Railway Co v Bates  3 KB 578
If a bailiff jams his boot into a debtors door to stop him closing, any levy that is subsequently made is not valid: Rai & Rai v Birmingham City Council  or Vaughan v McKenzie  1 QB 557 or Broughton v Wilkerson  44 JP 781
If a bailiff refuses to leave the property after being requested to do so or starts trying to force entry then he is causing a disturbance, Howell v Jackson  6 C&P 723 - but it is unreasonable for a police officer to arrest the bailiff unless he makes a threat, Bibby v Constable of Essex  Court of Appeal April 2000.
Vaughan v McKenzie  1 QB 557 if the debtor strikes the bailiff over the head with a full milk bottle after making a forced entry, the debtor is not guilty of assault because the bailiff was there illegally, likewise R. v Tucker at Hove Trial Centre Crown Court, December 2012 if the debtor gives the bailiff a good slap.
If a person strikes a trespasser who has refused to leave is not guilty of an offence: Davis v Lisle  2 KB 434